A competitive enzyme-linked immunosorbent assay (CELISA) for antibody detection was developed by using a monoclonal antibody which reacts with a 15-kDa tegumental antigen of the adult worm of Schistosoma mansoni. This monoclonal antibody was not able to react with antigens of Schistosoma japonicum or Schistosoma haematobium in enzyme-linked immunoelectrotransfer blot (EITB) and indirect immunofluorescence tests. The assay was performed in a period of 1 h using an adult worm crude extract antigen. To evaluate the CELISA, a total of 73 serum samples was analyzed: 35 were from S. mansoni-infected patients, 23 were from individuals with parasitic infections other than schistosomiasis, and 14 were from healthy individuals. All serum samples from healthy individuals and from patients infected with other parasites were negative, as were two (6%) samples from patients infected with S. mansoni. EITB analysis showed that 32 of 33 CELISA-positive samples were positive in the EITB but with different patterns of reactivity. A 15-kDa protein reacted with 60% of serum samples, and a 60-kDa protein showed the highest level of reactivity (85%). The two samples from patients infected with S. mansoni that were negative in the CELISA reacted with 70-, 60-, 50-, 47-, and 38-kDa proteins. One sample, positive in CELISA, did not react with proteins of the antigenic extract.

Single unit recording of neurons in the orbitofrontal cortex of the alert rhesus monkey was used to investigate responses to sensory stimulation. 32.4% of the neurons had visual responses that had typical latencies of 100–200 ms, and 9.4% responded to gustatory inputs. Most neurons were selective, in that they responded consistently to some stimuli such as foods or aversive objects, but not to others. In a number of cases the neurons responded selectively to particular foods or aversive stimuli. However, this high selectivity could not be explained by simple sensory features of the stimulus, since the responses of some neurons could be readily reversed if the meaning of the stimulus (i.e. whether it was food or aversive) was changed, even though its physical appearance remained identical. Further, some bimodal neurons received convergent visual and gustatory inputs, with matching selectivity for the same stimulus in both modalities, again suggesting that an explanation in terms of simple sensory features is inadequate.

The literature of the past 4–5 yr on serodiagnosis and seroepidemiology of schistosomiasis is reviewed. A variety of assays with different antigens are being used for serodiagnosis. Several purified antigens appear to be sensitive and specific, but have little if any capability of indicating duration of infection, parasite burden, or effect of chemotherapy. The results of long-term posttherapy field studies indicate that serology has a role in monitoring control programs. Standardized serologic assays and the need for International Standard Reference Sera are emphasized. A standardized enzyme-linked immunosorbent assay based on the Falcon Assay Screening Test® system (FAST-ELISA), and involving a standard reference serum pool, is suitable for both serodiagnosis and field studies. Measurement of circulating antigens as a parameter of active infection is considered to have increased potential, compared with antibody measurement, in management of clinical disease and in control programs. Recombinant DNA technology may be useful for producing standard antigens for use in assays measuring antibody or circulating antigen. Time-resolved immunofluorescence involving europium-labeled conjugates may provide the increased assay sensitivity needed for measurement of circulating antigen.

Single unit recordings were made in the lateral hypothalamic region and ventrobasal thalamus in conscious sheep during presentation of food and feeding. Unit responses to all aspects of testing were observed between the two areas. However, analysis of the data revealed a functional division of unit types between the two regions. Unit responses specific to the sight of food, to the approach of food to the mouth, and during ingestion of food were observed in the lateral hypothalamic area, but not the ventrobasal thalamus. These responses were not associated with specific or generalized movements, non-specific arousal, with olfactory stimulation, or with other oral stimuli. Units responding in association with specific mouth movements or somatosensory stimulation of the face or mouth-parts were observed in the ventrobasal thalamus but not in the lateral hypothalamic area. In the case of movement-related activity, the response was independent of the stimulus inducing the movement, food and non-food stimuli being equally effective. This was also true of the somatosensory responses observed. Two possibilities in relation to this functional division are discussed. Firstly, that the ventrobasal thalamus receives oral sensory afferents which may be associated with the thalamic area for taste. Secondly, that the activity of hypothalamic cells recorded in the sheep is consistent with a role for this area of the brain in the guidance and control of ingestive behaviour in ruminant as well as non-ruminant species.

To analyze the function of the striatum, recordings are being made of the activity of striatal neurons while the striatum is functioning normally in the behaving monkey. The neuronal responses are being examined while the monkey performs tasks known to be impaired by damage to the striatum. One aspect of the findings is that the neuronal responses in different parts of the striatum reflect the activity of the cortical area, which projects most strongly to each region of the striatum. There is a projection from the inferior temporal visual cortex to the striatum, in particular to the tail of the caudate nucleus, which is in the temporal lobe, and the adjoining postero-ventral part of the putamen. The neostriatum contains assemblies of neurons with properties suggesting that they are involved in different stages by which environmental cues prepare animals and enable them to make behavioral responses.

Rhesus monkeys prepared with chronic cannulae implanted in the stomach and duodenum were water deprived for 22.5 hr. With both cannulae closed, a mean of 137 ml was drunk within a 60-min period. When ingested water drained freely from an open gastric cannula, continuous drinking far in excess (878 ml mean intake) of normal occurred. Sham drinking also exceeded (634 ml mean intake) normal when ingested water drained through an open duodenal cannula. This pattern of continuous sham drinking indicates that oropharyngeal stimulation is not sufficient alone, or together with the passage of water through the stomach and the initial part of the duodenum, to terminate drinking. Duodenal infusions of water (25-100 ml) slowed or stopped gastric sham drinking in a dose-dependent fashion, but equivalent infusions of isotonic saline were without effect. Thus, pre- or postabsorptive signals at or beyond the level of the intestine distal to the site of the duodenal cannula are probably important for the termination of drinking in the rhesus monkey.

The effect of 24-hr water deprivation and subsequent drinking on systemic fluid balance was determined in rhesus monkeys prepared with indwelling cardiac catheters. Significant intracellular and extracellular depletions, as indicated by increased plasma sodium concentrations, osmolality, and plasma protein concentrations, resulted from the deprivation. An early attenuation in rehydrational drinking rate (2--4 min) was not associated with changes in systemic fluid balance, which suggests presystemic influences on behavior at this time. When drinking terminated (10 min), however, plasma dilution was significant. In experiments in which monkeys were sham drinking (open gastric cannula), water but not isotonic saline infusions, given through an intestinal cannula, reduced drinking rate and produced significant plasma dilution. Intravenous water infusions reduced drinking to only a comparable extent despite more rapid and substantial plasma dilution. Thus, systemic absorption does not account entirely for the effect of intestinal water infusions on drinking. It is concluded that stimulation of mechanisms both presystemically (within the intestine or the hepatic portal circulation) and systemically is important in the control and termination of rehydrational drinking in this species.

This chapter describes activity of neurons in the neostriatum and related structures in the alert animal. Movement-related neuronal activity has been found in the caudate nucleus of the monkey. In recordings made in the caudate nucleus and putamen of the monkey, it was found that the activity of some neurons is related to movements made by the monkey, although it is usually more difficult than with neurons in the globus pallidus to demonstrate a strong relation between neuronal activity and a particular movement. An example of the activity of a caudate neuron with movement-related activity is as follows. The neuron had a slow spontaneous firing rate of 2 spikes/s, and increased its rate when the monkey extended his contralateral arm to depress an illuminated panel. The unit responded during extension of the arm to reach the panel or during pressing the panel with the fingers if the arm was already extended. The response illustrated was related to movement of the contralateral arm and similar, but smaller responses were obtained with movements of the ipsilateral arm and hand.

Single unit discharges in the ventromedial hypothalamic nucleus (VMH) and lateral hypothalamic area (LH) were extracellularly recorded in urethane anesthetised female rats, while various solutions were perfused through the stomach or duodenum via implanted polythene tubes. Perfusates, which were maintained at 38°C, were 0.9% (w/v) NaCl, 2.5% NaCl, 5.25% glucose, 30% glucose, 5.0% casein hydrolysate, and liquid food. Only units which did not respond to somatosensory stimuli were tested. One hundred and twenty six units were recorded for periods of up to 3 hr, occasionally longer, in 57 animals. Of these, 74 were recorded during gastric perfusions and 52 during duodenal perfusions. Distension of the stomach elicited changes in firing rate in 16 LH and 8 VMH units. Both increases and decreases in firing rate in response to gastric distension were observed in both the LH and VMH. There was no evidence that nutrient or osmotic properties of the perfusates exerted any modifying influence on hypothalamic unit discharges. Distention of the duodenum by the perfusions elicited changes in firing rate in 12 LH and 6 VMH units. In this case all LH units decreased firing and all VMH units increased firing during distension of the lumen. In addition 2 VMH units appeared to increase their firing rate in association with glucose perfusions. The results are discussed in terms of the role of gastrointestinal feedback to the hypothalamus in food intake regulation.

The inhibition hypothesis advocated by Ekman (1985) states when an emotion is concealed or masked, the true emotion is manifested as a micro-expression (ME) which is a fleeting expression lasting for 40 to 500 ms. However, research about the inhibition hypothesis of ME from the perspective of electrophysiology is lacking. Here, we report the electrophysiological evidence obtained from an electroencephalography (EEG) data analysis method. Specifically, we designed an ME elicitation paradigm to collect data of MEs of positive emotions and EEG from 70 subjects, and proposed a method based on tensor component analysis (TCA) combined with the Physarum network (PN) algorithm to characterize the spatial, temporal, and spectral signatures of dynamic EEG data of MEs. The proposed TCA-PN methods revealed two pathways involving dorsal and ventral streams in functional brain networks of MEs, which reflected the inhibition processing and emotion arousal of MEs. The results provide evidence for the inhibition hypothesis from an electrophysiological standpoint, which allows us to better understand the neural mechanism of MEs.

Intraperitoneal injection of 20 I.D.U./kg of cholecystokinin (CCK), a gut hormone, depressed food intake in female rats as measured by an operant response for food. The effect was maximal thirty min after the injection and lasted 60–90 min. Intracranial injection of 0.05, 0.10, or 0.20 I.D.U. of CCK into the lateral ventricle of female rats, produced a dose-related depression of food-rewarded lever pressing. In this case, however, the effect was not observed during the first thirty min, but became apparent thereafter. The results are discussed in terms of possible receptors for CCK within the brain.