Recent advances in our understanding of tau pathophysiology, in particular “prion-like” spread of tau, have only highlighted pathological tau as a prime therapeutic target for Alzheimer's disease (AD) and other tauopathies. Tau aggregates can act as ‘seeds’ that promote further tau aggregation and spread to structurally connected brain regions; a process termed tau propagation. Although the exact mechanism(s) involved are not fully understood, numerous in vivo models of tau propagation have been developed. These models rely on either discrete regional tau over-expression or intracerebral infusion of tau aggregates; however, are these models relevant to human disease and preclinical drug-discovery? In this study we compare and contrast a range of in vivo models we have developed and optimised for pre-clinical drug-discovery. Tau transgenic (P301S and hTau) and wild-type (C57/BL6) mice were stereotaxically infused with tau protein extracted from mouse brain (P301S and C57/BL6) or post-mortem AD brain tissue. Mice were analysed neuropathologically at defined time-points post-infusion to analyse the accumulation and spread of tau pathology. Tau extracts prepared from C57/BL6 mice did not induce tau propagation in vivo. In contrast, rapid and robust tau propagation was observed when P301S mice were infused with tau extracts derived from symptomatic P301S mice; however, such accumulation and spread of tau pathology was not observed when the same seed was infused into hTau mice. Interestingly, tau protein extracts derived from post-mortem AD brain tissue had variable results on the distribution, progression and severity of tau pathology when infused into different transgenic and wild-type mice. Immunodepletion of pathological tau from the extract prevented any tau accumulation or spread. We have developed and optimised a range of in vivo tau propagation models that demonstrate seeded-aggregation and spread of tau pathology. The severity, distribution and progression of tau pathology were different in these models and therefore will affect their utility and relevance for pre-clinical drug-discovery.

In Alzheimer's disease (AD), the regional spread and intensity of tau correlates with clinical progression. Mechanistically, the spread of tau pathology has been proposed to be via a prion-like mechanism. As such, effectively neutralizing extracellular transmissible tau (“seeds”), for example via an antagonistic antibody, may block tau propagation. We have previously shown positive in vivo effect of immunotherapy with anti-tau antibodies MC-1 and PHF-1 (Chai et al. 2011 J Biol Chem). To determine targeting which tau epitope may be most effective, we compared activities of a series of tau antibodies targeting various epitopes, including aggregated tau (MC-1), phosphorylated tau (PHF-1, AT-8) and all tau forms (DA-9). We established several cell-based and in vivo tau propagation models to determine and rank the antibody's ability to neutralize tau seeds and reduce tau pathology. We further tested the antibodies in an in vivo chronic efficacy model where each antibody was peripherally administered for four months in JNPL3 mice. In the in vivo neutralization model, where antibody and tau seeds were co-injected into the brain of P301S mice, aggregate-selective antibody MC-1 blocked pathology induced by injected tau seeds. Similar results were obtained in a HEK293-P301S cell model where MC-1 showed the highest Emax (maximum effect) to block tau propagation. To investigate why MC-1 was showed the highest Emax, each antibody was conjugated to beads and incubated with tau seeds, and antibody-depleted seeds were tested for their seeding capability. All tau antibodies had significant effect to reduce seeding activity, however, only MC-1 showed near complete removal of the seeding activity. Biochemically, the MC-1-depleted seeds showed the lowest levels of remaining high-molecular-weight tau aggregates. In JNPL3 mice, MC-1 demonstrated consistent activity to reduce tau pathology. Among antibodies tested that target various tau epitopes, aggregate-selective antibody MC-1 demonstrated superior in vitro activity to neutralize transimissible tau and consistent in vivo activity to reduce tau pathology in the JNPL3 mouse model. Our results suggest a potential therapeutic efficacy of an aggregate-selective tau antibody for AD treatment.

Abnormal alpha-synuclein (alpha-synudein) expression and aggregation is a key characteristic of Parkinson's disease (PD). However, the exact mechanism(s) linking alpha-synudein to the other central feature of PD, dopaminergic neuron loss, remains unclear. Therefore, improved cell and in vivo models are needed to investigate the role of alpha-synudein in dopaminergic neuron loss. MicroRNA-7 (miR-7) regulates alpha-synudein expression by binding to the 3 ' UTR of the Synuclein Alpha Non A4 Component of Amyloid Precursor (SNCA) gene and inhibiting its translation. We show that miR-7 is decreased in the substantia nigra of patients with PD and, therefore, may play an essential role in the regulation of alpha-synudein expression. Furthermore, we have found that lentiviral-mediated expression of miR-7 complementary binding sites to stably induce a loss of miR-7 function results in an increase in alpha-synudein expression in vitro and in vivo. We have also shown that depletion of miR-7 using a miR-decoy produces a loss of nigral dopaminergic neurons accompanied by a reduction of striatal dopamine content. These data suggest that miR-7 has an important role in the regulation of alpha-synudein and dopamine physiology and may provide a new paradigm to study the pathology of PD.

Intraneuronal inclusions composed of aggregated tau are the pathological hallmark of a group of neurodegenerative diseases termed tauopathies. Recent studies have demonstrated that tau aggregates not only act as seeds for further tau aggregation, but can also spread to structurally connected brain regions. This process has been termed tau propagation and, although the exact mechanism(s) involved are not fully understood, it is a possible explanation for the stereotypical progression of tau pathology observed in tauopathies such as Alzheimer’s disease. In the current study, we investigate the role of axonal pathways in spreading tau pathology in vivo using our previously reported P301S tau propagation (P301S-TP) model. The P301S-TP model was developed by infusing brains extracts (containing aggregated tau) from old P301S mice (5 months) into the hippocampus of young P301S mice (2 months). Animals were then aged up to 2.5 months post-infusion, before being processed for neuropathological assessment using markers for pathological tau. In this study, specific axonal pathways were transected in P301S at 1 month prior to the infusion of aggregated tau at 2 months, as described above. A sham group were treated in a similar fashion but were not transected. Both groups were analysed neuropathologically for evidence of tau propagation. Consistent with previous P301S-TP data, sham-treated mice developed robust tau pathology in the hippocampus and showed evidence of spread to structurally connected regions. Transected mice had a comparable amount of hippocampal tau pathology, but showed significantly reduced pathology in regions that are connected to the hippocampus via the transected axonal pathway. Spread to regions connected by different axonal pathways was unaffected. Transection of specific axonal pathways in P301S-TP mice did not affect the accumulation of tau pathology in the hippocampus (site of infusion) but was sufficient to inhibit the spread of tau pathology to regions that were structurally connected via the transected pathway. These data confirm that axonal pathways act as conduits, enabling the spread of tau pathology along anatomical networks. Ultimately, a better understanding of the underlying mechanism(s) of tau propagation will help design better therapeutics to inhibit this process.

The interneuronal propagation of aggregated tau is believed to play an important role in the pathogenesis of human tauopathies. It requires the uptake of seed-competent tau into cells, seeding of soluble tau in recipient neurons and release of seeded tau into the extracellular space to complete the cycle. At present, it is not known which tau species are seed-competent. Here, we have dissected the molecular characteristics of seed-competent tau species from the TgP301S tau mouse model using various biochemical techniques and assessed their seeding ability in cell and animal models. We found that sucrose gradient fractions from brain lysates seeded cellular tau aggregation only when large (>10 mer) aggregated, hyperphosphorylated (AT8- and AT100-positive) and nitrated tau was present. In contrast, there was no detectable seeding by fractions containing small, oligomeric (<6 mer) tau. Immunodepletion of the large aggregated AT8-positive tau strongly reduced seeding; moreover, fractions containing these species initiated the formation and spreading of filamentous tau pathology in vivo, whereas fractions containing tau monomers and small oligomeric assemblies did not. By electron microscopy, seed-competent sucrose gradient fractions contained aggregated tau species ranging from ring-like structures to small filaments. Together, these findings indicate that a range of filamentous tau aggregates are the major species that underlie the spreading of tau pathology in the P301S transgenic model. Significance statement: The spread of tau pathology from neuron to neuron is postulated to account for, or at least to contribute to, the overall propagation of tau pathology during the development of human tauopathies including Alzheimer's disease. It is therefore important to characterize the native tau species responsible for this process of seeding and pathology spreading. Here, we use several biochemical techniques to dissect the molecular characteristics of native tau protein conformers from TgP301S tau mice and show that seed-competent tau species comprise small fibrils capable of seeding tau pathology in cell and animal models. Characterization of seed-competent tau gives insight into disease mechanisms and therapeutic interventions.

The trans-synaptic spread of tau pathology from neuron to neuron is thought to account for, or at least to contribute to, the overall propagation of tau pathology during the development of human tauopathies including Alzheimer’s disease. It is therefore important to characterize the native tau species responsible for this process of seeding and pathology spreading. Here, we have dissected the molecular characteristics of tau involved in seeding and spread in cell culture and animal model systems. Total brain lysate from TgP301S was subjected to sucrose gradient fractionation, and fractions were assessed for seeding ability using a cell-based assay for tau propagation and by immuno-EM and non-denaturing gels. TgP301S total brain lysate was subjected to immunodepletion using total and phospho-tau antibodies and depleted fractions were assessed for seeding ability in the same cell-based model. These cell-based studies were confirmed using an in vivoP301S tau propagation model. Furthermore, the seed-competent tau species released into the media of cells were also characterised using various biochemical techniques. Sucrose gradient fractions from symptomatic TgP301S total brain lysate were able to seed intracellular tau aggregation only when AT8/AT100 positive hyperphosphorylated tau was detectable, and did not seed when AT8 positive tau was absent. Moreover seed-competent fractions were shown to contain sarkosyl-insoluble aggregated tau species. Immuno-EM of sucrose gradient fractions demonstrated that seed-competent fractions contained fibrillar tau species. Immunodepletion of the large aggregated AT8 positive tau strongly reduced seeding; moreover, fractions containing these species initiated the formation and spreading of filamentous tau pathology in vivo,while fractions containing tau monomers and small oligomeric assemblies did not. Finally, seed-competent tau released into the media also contained sarkosyl-insoluble AT8 positive tau that was able to seed naïve cells. Taken together, the findings suggest that a diverse population of filamentous aggregates are capable of seeding and promoting the spread of tau pathology, with the most potent species being short fibrils. Importantly, we did not observe any evidence of seeding by small oligomeric (<6mer) tau species. These studies are accelerating our molecular understanding of disease processes and have important implications for the development of new therapeutics.

Several lines of evidence indicate that Glial cell line-derived neurotrophic factor (GDNF) is a trophic factor for dopaminergic neurons. Direct parenchymal administration of GDNF is robustly neuroprotective and neurorestorative in multiple neurotoxin-based animal models (rat and non-human primate (NHP)) of Parkinson's Disease (PD), suggesting its potential as a therapeutic agent. Although small, open-label clinical trials of intra-putamenal administration of bacteria-derived, full length, wild type GDNF (GDNFwt) were efficacious in improving standardized behavioral scores, a double-blinded, randomized controlled trial failed to do so. We hypothesize that the lack of clinical efficacy of GDNFwt in the larger randomized trial was due to poor bio-distribution in the putamen and/or poor chemical stability while in the delivery device for prolonged time periods at 37°C. The development of neutralizing antibodies in some patients may also have been a contributing factor. GDNFv is an engineered form of GDNFwt, expressed and purified from mammalian cells, designed to overcome these limitations, including removal of the N-terminal heparin-binding domain to improve its diffusivity in brain parenchyma by reducing its binding to extracellular matrix (ECM), and key amino acid substitutions to improve chemical stability. Intra-striatal administration of a single injection of GDNFv in the rat produced significantly greater brain distribution than GDNFwt, consistent with reduced binding to ECM. Using liquid chromatography/mass spectrometry (LS/MS) methods GDNFv was shown to have improved chemical stability compared to GDNFwt when stored at 37°C for 4weeks. In addition, GDNFv resulted in lower predicted clinical immunogenicity compared to GDNFwt, as demonstrated by reduced CD4+ T cell proliferation and reduced IL-2-induced secretion in peripheral blood mononucleated cells collected from volunteers representing the world's major histocompatibility complex (MHC) haplotypes. GDNFv was demonstrated to be pharmacologically equivalent to GDNFwt in the key parameters in vitro of GFRα1 receptor binding, c-Ret phosphorylation, neurite outgrowth, and in vivo in its ability to increase dopamine turnover (DA). GDNFv protected dopamine nerve terminals and neurons in a 6-hydroxy-dopamine (6-OHDA) rat model. In summary, we empirically demonstrate the superior properties of GDNFv compared to GDNFwt through enhanced bio-distribution and chemical stability concurrently with decreased predicted clinical immunogenicity while maintaining pharmacological and neurotrophic activity. These data indicate that GDNFv is an improved version of GDNF suitable for clinical assessment as a targeted regenerative therapy for PD.

Intracellular inclusions composed of hyperphosphorylated filamentous tau are a hallmark of Alzheimer’s disease, progressive supranuclear palsy, Pick’s disease and other sporadic neurodegenerative tauopathies. Recent in vitro and in vivo studies have shown that tau aggregates do not only seed further tau aggregation within neurons, but can also spread to neighbouring cells and functionally connected brain regions. This process is referred to as ‘tau propagation’ and may explain the stereotypic progression of tau pathology in the brains of Alzheimer’s disease patients. Here, we describe a novel in vivo model of tau propagation using human P301S tau transgenic mice infused unilaterally with brain extract containing tau aggregates. Infusion-related neurofibrillary tangle pathology was first observed 2 weeks post-infusion and increased in a stereotypic, time-dependent manner. Contralateral and anterior/posterior spread of tau pathology was also evident in nuclei with strong synaptic connections (efferent and afferent) to the site of infusion, indicating that spread was dependent on synaptic connectivity rather than spatial proximity. This notion was further supported by infusion-related tau pathology in white matter tracts that interconnect these regions. The rapid and robust propagation of tau pathology in this model will be valuable for both basic research and the drug discovery process.

Tau proteins have been shown to be transmissible between neurons and can act as nucleating agents to promote tau fibril formation (or seeding). However, the nature of the tau species required for seeding remains elusive. Here, we have assessed the seeding ability of tau protein fractions from TgP301S mice following separation using sucrose gradients and immunodepletion. Total brain lysate from TgP301S was subjected to sucrose gradient fractionation, and fractions were assessed for seeding ability using a cell-based assay for tau propagation and by immuno-EM and non-denaturing gels. TgP301S total brain lysate was subjected to immunodepletion using total and phospho-tau antibodies and depleted fractions were assessed for seeding ability in the same cell-based model. Quantification of tau and hyperphosphorylated tau detected with multiple phospho-tau antibodies was carried out after seeding by ELISA/Alphascreen and Western blot analysis. These cell-based studies were confirmed using an in vivo P301S tau propagation model. When applied to a cell-based model of tau propagation, sucrose gradient fractions from total brain lysate were able to seed intracellular tau aggregation only when AT-8 positive hyperphosphorylated tau was detectable, and did not seed when AT-8 positive tau was absent. Moreover seed-competent fractions were shown to contain aggregated tau species based on analysis on non-denaturing gels. Immuno-EM of sucrose gradient fractions also demonstrated that seed-competent fractions contained fibrillar tau species. Immunodepletion of AT-8 positive tau from soluble tau fractions reduced their ability to seed. Finally, co-infusion of P301S brain lysate and the AT-8 antibody into a mouse model of tau propagation showed reduced levels of neurofibrillary pathology. Together these results indicate that seed competent tau species in this assay are aggregated and hyperphosphorylated. The precise size of the major seed competent species remains to be determined, however it seems likely, based on our data that a diverse population of filamentous aggregates is capable of seeding tau pathology in this assay, with these species likely generated by filament fragmentation or secondary nucleation. Importantly, we did not observe any evidence of seeding by small oligomeric (<5mer) tau species.

O1-07-02 IMPACTAND BLAST NEUROTRAUMA MOUSE MODELS OF CHRONIC TRAUMATIC ENCEPHALOPATHY VALIDATED BY HUMAN NEUROPATHOLOGY Andrew Fisher, Lee Goldstein, Chad Tagge, Libor Velisek, Mark Wojnarowicz, Robert Moir, Noel Casey, Juliet Moncaster, Christopher Nowinski, Jan Blusztajn, Benjamin Wolozin, Carmela Abraham, Sudad Saman, Chirag Upreti, Tsuneya Ikezu, Robert Stern, John Sullivan, Cezar Goletiani, Olga Minaeva, Thor Stein, Andrew Budson, Neil Kowall, Robert Cantu, Maria Ericsson, Robin Cleveland, William Moss, Garth Hall, Rudolph Tanzi, Patric Stanton, Ann McKee, Boston University, Boston, Massachusetts, United States; Boston University School of Medicine, Boston, Massachusetts, United States; New York Medical College, Valhalla, New York, United States; Massachusetts General Hospital/Harvard Medical School, Charlestown, Massachusetts, United States; Boston University Center for Biometals & Metallomics, Boston, Massachusetts, United States; University of Massachusetts Lowell, Lowell, Massachusetts, United States; NYMC, Valhalla, New York, United States; Boston VA Medical Center, Boston, Massachusetts, United States; Boston University Alzheimer’s Disease Center, Boston, Massachusetts, United States; Harvard Medical School, Boston, Massachusetts, United States; University of Oxford, Oxford, United Kingdom; Livermore National Laboratory, Livermore, California, United States; University of Massachusetts Lowell, Lowell, Massachusetts, United States. Contact e-mail: lgold@ bu.edu

Aberrant intracellular inclusions composed of hyperphosphorylated filamentous tau are a neuropathological hallmark of Alzheimer's disease, progressive supranuclear palsy and other sporadic neurodegenerative disorders, which have been collectively termed tauopathies. The discovery that pathogenic mutations in the tau gene (MAPT) can cause a familial neurodegenerative tauopathy has provided compelling evidence that tau dysfunction is sufficient to cause neurodegeneration. Therefore inhibiting potentially toxic events such as tau inclusion formation are attractive targets for therapeutic intervention and disease prevention. A string of recent in vitro and in vivo studies have shown that tau aggregates have 'prion-like' properties which not only allow them to transmit/seed further tau aggregation, but also spread to neighbouring cells or connected brain regions. This process is referred to as 'tau propagation' and might explain the stereotypic progression of tau pathology in Alzheimer's disease and other tauopathies. In this study, we report a novel in vivo model of tau propagation using young asymptomatic P301S transgenic mice that underwent unilateral hippocampal infusions containing brain extracts from older clinically impaired P301S mice, known to have florid tau aggregates. Detailed neuropathological examination was conducted in these mice (and controls) at various time-points post-infusion to investigate the presence and distribution of tau pathology. Infusion-related tau pathology was induced rapidly (within 2 weeks) in the hippocampus of this model. Tau-positive neurofibrillary tangles increased in a stereotypic and progressive fashion, with robust Gallyas-positive tangles being observed 1 month post-infusion. Contralateral and anterior/posterior spread of tau pathology was also evident and appeared to be dependent on synaptic connectivity rather than spatial proximity. Tau biochemistry confirmed the induction and spread of tau pathology in this model. Previously reported models of tau propagation take several months to develop significant tau pathology attributable to propagation, therefore the rapid and robust propagation phenotype in our model will be instrumental to both basic research and the drug discovery process, with the ultimate aim to find intervention and prevention strategies for human tauopathies.

SAR around a known molecule with dual 5-HT(1D) antagonist and 5-HT(transporter) inhibitory activity has led to the discovery of molecules with improved dual activity and reduced cross-reactivity toward other aminergic receptors (5-HT(1B), alpha(1), and D(2)).

Incorporation of an SRI (serotonin reuptake inhibitor) pharmacophore into a selective 5-HT(1D) agonist has led to the discovery of a molecule having both 5-HT(1D) antagonist and SRI activity. RPS methodology was used to develop the SAR and identify potential approaches to reduce unwanted adrenergic alpha 1 and dopamine D(2) cross-reactivities.

The present study investigated the role of the 5-hydroxytryptamine (5-HT, serotonin)1D receptor as a presynaptic autoreceptor in the guinea pig. In keeping with the literature, the 5-HT1B selective antagonist, 1'-methyl-5-[[2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)biphenyl-4-yl]carbonyl]-2,3,6,7-tetrahydrospiro [furo[2,3-f]indole-3,4'-piperidine]oxalate (SB224289) potentiated [3H]5-HT outflow from pre-labelled slices of guinea pig cerebral cortex confirming its role as a presynaptic autoreceptor in this species. In addition, the 5-HT1D receptor-preferring antagonists, 1-[2-[4-(6-fluoro-1H-indol-3-yl)-3,6-dihydro-2H-pyridin-1-yl]-ethyl]-3-pyridin-4-yl-methyl-tetrahydro-pyrimidin-2-one (LY367642), (R)-1-[2-(4-(6-fluoro-1H-indol-3-yl-)-3,6-dihydro-1(2H)-pyridinyl)ethyl]-3,4-dihydro-1H-2-benzopyran-6-carboxamide (LY456219), (S)-1-[2-(4-(6-fluoro-1H-indol-3-yl-)-3,6-dihydro-1(2H)-pyridinyl)ethyl]-3,4-dihydro-1H-2-benzopyran-6-carboxamide (LY456220) and 1-[2-[4-(4-fluoro-benzoyl)-piperidin-1-yl]-ethyl]-3,3-dimethyl-1,2-dihydro-indol-2-one (LY310762), potentiated [3H]5-HT outflow from this preparation with potencies (EC50 values=31-140 nM) in the same range as their affinities for the guinea pig 5-HT1D receptor (Ki values=100-333 nM). The selective 5-HT1D receptor agonist, R-2-(4-fluoro-phenyl)-2-[1-[3-(5-[1,2,4]triazol-4-yl-1H-indol-3-yl)-propyl]-piperidin-4-ylamino]-ethanol dioxylate (L-772,405), inhibited [3H]5-HT outflow. In microdialysis studies, administration of either SB224289 or LY310762 at 10 mg/kg by the intraperitoneal (i.p.) route, potentiated the increase in extracellular 5-HT concentration produced by a maximally effective dose of the selective serotonin re-uptake inhibitor, fluoxetine (at 20 mg/kg i.p.). In addition, the 5-HT1D receptor-preferring antagonist and 5-HT transporter inhibitor, LY367642 (at 10 mg/kg i.p.), elevated extracellular 5-HT concentrations to a greater extent than a maximally effective dose of fluoxetine. It is concluded that the 5-HT1D receptor, like the 5-HT1B receptor, may be a presynaptic autoreceptor in the guinea pig.

The stimulation of terminal 5-HT(1B/1D) autoreceptors limits the effects of selective serotonin reuptake inhibitors on extracellular levels of 5-hydroxytryptamine (5-HT, serotonin) in vivo. Microdialysis studies show that acute oral administration of LY393558-a 5-HT reuptake inhibitor and antagonist at both the human 5-HT(1B) and 5-HT(1D) receptor-in the dose range 1-20 mg/kg, increases extracellular levels of 5-HT in both the guinea pig hypothalamus and rat frontal cortex. In both species, the levels of 5-HT that were attained were higher than following an acute, maximally effective dose of fluoxetine (20 mg/kg orally), reaching approximately 1500% in the guinea pig hypothalamus and 700% in the rat frontal cortex. In both species, the response to LY393558 (10 mg/kg p.o.) was impulse dependent, being absent in the presence of tetrodotoxin delivered at 1 microM via the microdialysis probe. The sensitivity to tetrodotoxin contrasted with the effects seen with DL-fenfluramine. Studies in rats showed that the microdialysate 5-HT concentration achieved in the frontal cortex after an acute challenge with LY393558 (5 mg/kg p.o.) was significantly greater than following a chronic regime of fluoxetine treatment (10 mg/kg/day orally for 21 days). Moreover, in rats chronically treated with LY393558 (5 mg/kg/day orally for 21 days), the mean basal concentration, 24 h after the final pretreatment dose, was of the same magnitude as that following chronic fluoxetine. However, in contrast to the response seen in fluoxetine-pretreated animals, a challenge dose of LY393558 still elicited a further increase in extracellular 5-HT in LY393558-pretreated animals. LY393558 is a potent 5-HT reuptake inhibitor and 5-HT(1B/1D) receptor antagonist. Microdialysis studies show that acute oral administration increases extracellular levels of 5-HT, by an impulse-dependent mechanism, above those produced by a maximally effective dose of fluoxetine, and in rats to levels only achieved following chronic fluoxetine treatment. Its neurochemical profile in vivo suggests that it may be a more effective antidepressant with the potential for producing an earlier onset of clinical activity than selective serotonin reuptake inhibitors.

Lipodermatosclerosis is a clinical disorder that includes acute inflammatory and chronic fibrotic stages.1 The chronic form is characterized by unilateral or bilateral hyperpigmented induration of the distal lower extremities, primarily in female patients with venous insufficiency. The indurated plaques are often painful and the legs frequently have a characteristic "inverted wine bottle" appearance. In addition, ulceration may develop and healing is often delayed. Therapeutic options for lipodermatosclerosis include elevation, compression stockings, ultrasound therapy, and oral stanozolol.

Somatostatin (or somatotropin-release inhibitory factor, SRIF) binding and in situ hybridisation studies have indicated a high expression of receptor subtypes throughout the rat brain and, in particular, in subregions of the hippocampus and subiculum. In vitro, somatostatin and related peptides, including seglitide (MK-678), hyperpolarize subicular neurones of the burst firing type-a response, which may have functional consequences for their output. One major projection from the subiculum is to the nucleus accumbens. The functional consequence of somatostatin receptor stimulation in the ventral subiculum has been assessed by measuring extracellular levels of dopamine in the ipsilateral nucleus accumbens. In anaesthetised rats, administration of seglitide (MK-678), a somatostatin analogue with selectivity for the SRIF-1 receptor (comprising somatostatin sst2, sst3 and sst5 subtypes) significantly increased extracellular levels of dopamine in the ipsilateral nucleus accumbens shell. The result suggests that hyperpolarization of subicular neurones by MK-678 may lead to activation of the subiculo-accumbens projection system, and an associated increase in dopaminergic function.