Recent research indicates that electroacupuncture could help patients suffering from Alzheimer's disease. Indeed, certain acupoints, when stimulated by electric pulses, activate particular parts of the brain, the details of which have been revealed by magnetic resonance imaging and positron emission tomography. Observed stimulated regions of the brain of Alzheimer's patients can be compared with the images obtained by fluorescence technique with a proper dye in Alzheimer's brain sections. This article provides support based on Western medical science for the treatment of Alzheimer's with electroacupuncture. Electroacupuncture acts in different and efficient ways. First, the positive charge of the electric pulses helps to detach from the neuron or the neuron membranes beta amyloid peptides, which have been associated with the pathogenesis of the disease. In addition to this, the presence of the carboxyl group of beta amyloids suffers a torque in the presence of an electric field and creates a serious deformation. Lastly, the moderate shaking originating from the electric pulses facilitates the partial disintegration of the beta sheet, a frequent conformational change of the beta amyloid peptide.

The aim of this research was to find out the effects of ip morphine pretreatment in the extracellular content of the arginine, glutamate, aspartate and GABA levels in the anterior cingulate cortex in rats, during the formalin test (phase I). A combination of micro dialysis and Capillary Electrophoresis Zone and laser-induced fluorescence detection (CZE-LIFD) technique was used to measure the extracellular levels of amino acids in microdialized zones. The microdialysis probes were unilaterally implanted in the left anterior cingulate cortex of freely moving rats. The samples were collected every 30 seconds and derivatized with fluorescein isothiocianate. The arginine, glutamate, aspartate and GABA levels were measured in the CZE-LIFD device. Arginine (p<0.001) and glutamate levels (p<0.012) were significantly increased in the first few minutes following the formalin test (phase 1). Pretreatment with morphine suppressed the glutamate increase. A transient GABA level increase (p<0.001) was also detected. These experiments suggest that rapid changes in neurotransmitters levels were detected in the first few minutes of acute pain as revealed by the glutamate and arginine level increases in the anterior cingulate cortex. These changes could be related to the emotion of pain processing (fear and aversion). Morphine pretreatment produced an increase in GABA levels and a decrease in glutamate levels in the first few minutes. These findings may be related to euphoria and/or analgesia.

Brain microdialysis has been a valuable technique in the neuroscience field for more than 20 years. In vivo microdialysis in freely-moving rats allows measurement of neurotransmitter release in response to ongoing behaviors. In this chapter we review findings using microdialysis in the study of behavior reinforcement and inhibition. This literature leads to the development of the dopamine hypothesis of reward and the cholinergic hypothesis of aversion and their underlying neural circuitry. Within the context of natural rewards, we discuss many of the key findings using microdialysis in the nucleus accumbens, ventral tegmental area and hypothalamus to study feeding, water intake, and mating. Artificial rewards, such as intracranial self-stimulation and drug reward, are also reviewed. Finally, data are summarized that suggest a natural reward, sugar, may take on behavioral and neurochemical properties of an artificial reward, such as a drug of abuse, under certain conditions

Cognitive, behavioral, and motor impairments, during progressive human immunodeficiency virus type 1 (HIV‐1) infection, are linked to activation of brain mononuclear phagocytes (MP; perivascular macrophages and microglia). Activated MPs effect a giant cell encephalitis and neuroinflammatory responses that are mirrored in severe combined immunodeficient (SCID) mice injected with human monocyte‐derived macrophages (MDM). Whether activated human MDMs positioned in the basal ganglia affect hippocampal neuronal plasticity, the brain subregion involved in learning and memory, is unknown. Thus, immunohistochemical techniques were used for detection of newborn neurons (polysialylated neuronal cell adhesion molecule [PSA‐NCAM]) and cell proliferation (Ki‐67) to assay MDM effects on neuronal development in mouse models of HIV‐1 encephalitis. Immunodeficient (C.B.‐17/SCID and nonobese diabetic/SCID, NOD/SCID) and immune competent (C.B.‐17) mice were injected with uninfected or HIV‐1‐infected MDM. Sham‐operated or unmanipulated mice served as controls. Neuronal plasticity was evaluated in the hippocampal dentate gyrus (DG) at days 7 and 28. By day 7, increased numbers of Ki‐67 + cells, PSA‐NCAM + cells and dendrites in DG were observed in sham‐operated animals. In contrast, significant reductions in neuronal precursors and altered neuronal morphology paralleled increased microglial activation in both HIV‐1‐infected and uninfected MDM‐injected animals. DG cellular composition was restored at day 28. We posit that activated MDM induce inflammation and diminish DG neuronal plasticity. These data provide novel explanations for the cognitive impairments manifested during advanced HIV‐1 infection. © 2005 Wiley‐Liss, Inc.

The antipsychotic drugs (APDs) are fundamental tools in current psychiatric practice. A new generation of agents, the atypical APDs, represents an important progress in the treatment of psychotic disorders. Unfortunately, some of them induce excessive body weight gain (BWG), obesity, hyperglycemia and dyslipidemia in the following order: clozapine approximately equal to olanzapine > quetiapine > risperidone > ziprasidone = aripiprazole. Appetite stimulation is probably the main mechanism of BWG and this is strongly correlated with the APD affinity for H1 (histaminergic) and alpha1 (adrenergic) receptors. A composed ratio of the APD affinity for diverse neurotransmitters involved in food intake (FI) regulation correlates with BWG as well. Endocrine/metabolic mechanisms, such as the activation of the hypothalamus-pituitary-adrenal axis, changes in insulin sensitivity (by conventional and atypical agents), hyperprolactinemia and gonadal dysfunction (by conventional APDs and risperidone) may also be involved. Importantly, patients with schizophrenia may have a genetically-based predisposition to appetite dysregulation, insulin resistance and endocrine imbalance involving gonadal steroids. Excessive BWG must be prevented or attenuated by proper drug selection, combining or switching agents, nutritional assistance and physical exercise. Amantadine. metformin and reboxetine proved to significantly lessen APD-induced BWG. Notwithstanding this, novel strategies are necessary to treat this side effect in a clinical population particularly prone to poor compliance and under a high risk of negative drug interaction.

Microdialysis is a simple technique that allows monitoring endogenous or exogenous substances in any extracellular compartment. It has many useful experimental and clinical applications. The sampling of the extracellular fluid of the subcutaneous compartment is especially useful for metabolic evaluation in critically ill patients, pharmacokinetic studies and blood glucose monitoring. We built a subcutaneous microdialysis probe, with a cellulose hollow fiber (13,000 molecular weight cut off, 200 microns outside diameter) glued to stainless steel tubing (26 ga. outside diameter). It was implanted in the subcutaneous tissue of a critically ill child or anesthetized mice to obtain amino acids patterns by means of capillary electrophoresis with laser induced fluorescence detection (CE-LIFD). The probe was also implanted in ambulatory volunteers to monitor glucose. The results confirmed that subcutaneous microdialysis is a very simple, inexpensive and not aggressive method with advantages over repeated venipuncture sampling and endovenous microdialysis sampling. The present report shows that subcutaneous microdialysis with the proper analytical technique can be used to monitor the chemical composition of the interstitial compartment in very different preclinical or clinical conditions.

Aims. The objective of this study is to survey present and future antidepressant drug therapy based on the progress made in the field of biotechnology. Development The simplistic and mistaken view that one single system of neurotransmission is altered in depression and that there is, therefore, just one single treatment has changed. Molecular biology and Genetics have enabled us to determine other possible chemical alterations in the brain, beyond the sole participation of the monoaminergic modulation systems, which is the classical hypothesis. In this paper we describe the evidence for the relations between depression and the therapeutic effect the classical antidepressants have on: 1. The peptidergic system of the corticotropin-releasing hormone, cortisol and the functional state of its receptors; 2.Intracellular signalling systems such as cAMP on transcription factors like CREB and neurotrophins; 3. The immune system and cytosines; 4. Glutamate transmission; and 5. The neuropeptidergic system of substance P, neuroactive steroids and the neuroglia. This has allowed other biochemical hypotheses about depression and the possibility of new treatments to be put forward. Conclusions. We are still not certain about the exact cause or the processes that determine mental illnesses such as depression or how improvements are achieved with the antidepressants we currently have available. Nevertheless, biotechnology is expected to be a great help in advancing towards a better understanding of the interrelations between the nervous, immune and endocrine systems, with their intracellular cascades and final outcomes in genetic expression and protein function, in depression. This will enable more efficient, more selective and faster-acting drugs to be developed and, in the future and with the help of psychogenomics, even make it possible to produce tailor-made medication for each patient.

Geranium has been traditionally used as a local hemostatic medicine in some Andean regions, but this effect has not been tested in controlled experiments. In the present report, the leaves of a geraniaceae (Pelargonium zonale) were tested on a bleeding rat model. The bleeding time was 50% shorter in the geranium leaf juice treatment group (18.10 ± 2.03 min) and 80% shorter in the geranium crushed‐leaf group (7.10 ± 0.88 min) than in the control (nontreatment) group (37.6 ± 3.04 min), p < 0.0001. Bleeding time with guava (Psidium guajava) crushed leaves (39.90 ± 1.54 min) was not different from the control group. A proved hemostatic agent, gelatin sponge, had a similar effect as geranium juice (16.7 ± 3.32 min) in the same animal model. A buffer solution at pH 3 (the same pH as the geranium leaf extract) did not have any hemostatic effect, and the bleeding time (39.3 ± 2.71 min) was not different from the control group. The dilution 1:4 geranium leaf juice at pH 3 (25.6 ± 3.08 min) or pH 5 (28.8 ± 3.98 min) still had a statistically significant hemostatic effect. The results confirm the hemostatic effect of P. zonale leaves and show that it is similar (geranium leaf juice) or better (crushed geranium leaves) than the hemostatic effect of a commercial hemostatic sponge. It seems that the hemostasis caused by P. zonale extract leaves is not due to its low pH. The potential benefits as a new, inexpensive, safe, and easily available natural topical hemostatic agent are discussed.

Scorpion human envenoming is a public health hazard in the southwest of Venezuela. Tityus zulianus is one of the scorpion species whose venom causes lung edema and cardiac failure in children. These occasionally deadly manifestations have been attributed to a massive sympathetic discharge. The intraperitoneal administration of T. zulianus venom (20 micrograms/g mouse) to anesthetized mice during subcutaneous microdialysis caused increased secretions, dyspnea, seizures and death between 30 min to 2 h. Seven amino acids were analyzed by capillary electrophoresis with laser induced fluorescence detection (CE-LIFD) in the collected samples before and after the venom administration. We found an increase of arginine (39%), phenylalanine (40%) and glutamate (94%), with no changes in valine, serine and aspartate, changes were significant when the injection of venom and vehicle were compared and before vs after venom injection. Further investigation is needed to know if the observed changes could be related to the molecular mechanisms of the venom or some of its components and therefore with the envenoming symptoms. To our knowledge, this is the first report with subcutaneous microdialysis and CE-LIFD coupling in scorpion envenomation studies in vivo, in mice.

Anatomical evidence indicates the presence of projections from the lateral hypothalamus to serotonergic (5-hydroxytryptamine, 5-HT) neurons of the dorsal raphe nucleus (DR). Using dual probe microdialysis and extracellular recordings in the DR, we show that the application of GABAergic agents in the lateral hypothalamus modulates the activity of 5-HT neurons in the DR. GABA and bicuculline or baclofen, applied in the lateral hypothalamus significantly reduced and increased, respectively, the 5-HT output in the DR. Likewise, the intrahypothalamic application of GABA and bicuculline reduced (14/20 neurons) and increased (8/12 neurons), respectively, the firing rate of 5-HT neurons in the DR. A smaller percentage of neurons, however, were excited by GABA (3/20) and inhibited by bicuculline (1/12). Application of tetrodotoxin in the lateral hypothalamus suppressed the local 5-HT output and reduced that in the DR. The 5-HT output in the DR increased transiently soon after darkness. The hypothalamic application of GABA attenuated and that of bicuculline potentiated this spontaneous change with an efficacy similar to that seen in light conditions. These results indicate that the lateral hypothalamus is involved in the control of 5-HT activity in the DR, possibly through excitatory (major) and inhibitory (minor) inputs.

Previous studies have shown that prolonged administration of antipsychotic drugs induces obesity in female but not in male rats. To explore the mechanisms involved in this sex-dependent effect, we administered the dopamine antagonist sulpiride (20 mg/kg i.p.) or vehicle (0.1 N HCl) to adult male rats during 21 days and daily assessed bodyweight and food intake. Then, we evaluated the glucose tolerance and the serum levels of insulin, leptin, total testosterone, dehydroepiandrosterone-sulfate (DHEA-S), thyroid hormones and blood lipids. In another experiment, food intake and water intake were assessed after acute injections of sulpiride or vehicle into the perifornical lateral hypothalamus. Lastly, the dopamine metabolites dihydroxyphenylacetic acid (DOPAC) and homovanilic acid (HVA) in the lateral hypothalamus were assessed by in vivo microdialysis after acute systemic injections of sulpiride and vehicle. Chronic sulpiride administration did not affect bodyweight gain and food intake. However, prolactin levels and the area under the glucose and insulin curves were significantly elevated. Acute sulpiride significantly increased food intake, water intake, DOPAC and HVA levels. The acute effects of sulpiride show that this drug is active at the perifornical lateral hypothalamus, which is a brain area where blockade of dopamine receptors stimulates feeding. However, after prolonged administration, sulpiride did not affect body weight. This lack of effect may be related to the impairment of insulin sensitivity, which may prevent body weight gain, and counteract other effects of sulpiride that promote adiposity such as hyperprolactinemia. These findings noticeably contrast with those observed in sulpiride-treated female rats that appear to display enhanced insulin sensitivity. The changes in insulin sensitivity do not appear related to a decrease in androgenic activity, because testosterone and DHEA-S levels were not affected by sulpiride. However, these results should be considered as preliminary because other relevant endocrine variables such as free testosterone, steroid binding globulin and pituitary gonadotrophin levels were not evaluated. Since the same sex-dependent effect on body weight and food intake in rats has been observed during administration of risperidone, which has a different pharmacological profile than sulpiride, future studies must evaluate other neurotransmitters involved in food intake regulation such as serotonin, noradrenaline and histamine.

Capillary electrophoresis (CE) is a high‐efficiency analytical technique that has had a great impact as a tool in biomedical research, clinical and forensic practice in the last ten years. Only in one of the applications, the DNA analysis, it has had an explosive exponential growth in the last few years. This impact is expressed in an enormous amount of CE articles and many reviews. The CE advantages with respect to other analytical techniques: the required very small sample volume, rapid analysis, great resolution power and low costs, have made this technique ideal for the analysis of a numerous endogenous and exogenous substances present in biological fluids. The different modes of CE have been coupled to different detection techniques such as UV‐absorbance, electrochemical, mass spectrometry and laser‐induced fluorescence detection (LIFD) to detect different nature and molecular size separated analytes. This review focuses mostly on the applications of CE–LIFD, to measure drugs and endogenous neuroactive substances such as amino acids and monoamines, especially in microdialysis samples from experimental animals and humans. CE–LIFD trends are discussed: automated faster analysis with capillary array systems, resolution power improvement, higher detection sensitivity, and CE systems miniaturization for extremely small sample volume, in order to make CE easier and affordable to the lab bench or the clinical bed. Copyright © 2001 John Wiley & Sons, Ltd.

Medial prefrontal cortex (MPFC) transection enhances social interaction in an open arena test. Social interaction enhances dopaminergic activity in the nucleus accumbens (NAC). In the present set of experiments, microdialysis probes were implanted in the NAC, and glutamate, γ-aminobutyric acid (GABA) and dopamine (DA) were measured during electrical stimulation of the MPFC, after coronal transection caudal to the MPFC and after a systemic injection of amphetamine in transected rats. Electrical stimulation of the MPFC caused a transient enhancement of glutamate release in the NAC, no change in GABA levels and a long lasting increase in DA levels. Medial prefrontal transection did not change basal glutamate or GABA levels in the NAC, but increased basal DA levels. Amphetamine administration decreased GABA levels in medial prefrontal transected rats, had no effect on glutamate and increased DA levels more than in controls. The experiments suggest that glutamatergic activity in the accumbens decreases dopamine release. Medial prefrontal transection reduces glutamatergic tone and enhances dopamine release, which probably decreases GABAergic activity in the NAC. Presumably, GABA inhibition in the NAC enhances social interaction.

Neutral and non-polar amino acids such as phenylalanine (Phe), valine (Val), tyrosine (Tyr), threonine (Thre) and GABA are hard to resolve by capillary zone electrophoresis (CZE). Their separation is possible by adding a surfactant to the mobile phase. This method is called micellar electrokinetic chromatography (MEKC). We used MEKC with laser-induced fluorescence detection (LIFD) to separate and quantitate these amino acids in plasma microdialysates of patients with phenylketonuria (PKU). This disease is an inborn enzymatic defect with decreased conversion of Phe to Tyr that causes severe neurological damage and mental deterioration, which is diagnosed by measuring plasma Phe and Phe/Tyr ratio. The amino acids tested had linear concentration–signal relation. PKU patients had significantly higher Phe, lower Tyr, 21 times higher Phe/Tyr ratio and decreased values of Val and Thre than controls. These results show that microdialysis of biological fluids coupled with MEKC–LIFD is a convenient technique to measure neutral amino acids in clinical disorders such as PKU.

Due to its low electrophoretic mobility, few studies have been able to measure gamma aminobutyric acid (GABA) in biological samples by means of capillary zone electrophoresis. Nevertheless, in micellar electrokinetic chromatography (MEKC) by adding a surfactant to the mobile phase separation can be carried out on the basis of the partition coefficient of the molecules rather than their electrophoretic mobility. In the present study microdialysis coupled to MEKC with laser induced fluorescence detection was used to successfully monitor GABA from cerebrospinal fluid and plasma dialysates. Moreover, we monitored changes in extracellular GABA from a human brain. Microdialysis samples were collected from a Parkinson's disease patient undergoing a thallamotomy as part of her treatment. Significant decreases in extracellular GABA were detected during high frequency electrical stimulation and following a thermolesion of the thalamus. These results demonstrate the feasibility of MEKC coupled to laser-induced fluorescence detection in resolving neutral amino acids, specifically GABA, from different human body fluids.