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T I Lidsky

Publications and source records attributed to T I Lidsky.

9 recordsLinked to original sources
PubMed1992

Clozapine's mechanisms of action: non-dopaminergic activity rather than anatomical selectivity.

The mechanisms of clozapine's unusual actions were investigated in anesthetized rats. Sensory field potentials were recorded in the nucleus accumbens, striatum and somatosensory cortex. Both haloperidol and clozapine suppressed responses in the striatum and accumbens. Clozapine's but not haloperidol's subcortical actions were unaffected by dopamine depletion. In addition, the cortical effects of the two drugs differed. These data indicate that clozapine has non-dopaminergic activity but no particular specificity for limbic basal ganglia structures. While it is known that clozapine acts as a serotonergic and cholinergic antagonist, several considerations suggest that action on still another transmitter system, possibly glutamate, needs to be investigated.

Animals↗
PubMed1979

Implications of basal ganglionic dysfunction for schizophrenia.

This paper is addressed to presenting evidence that the basal ganglia are involved in mediating schizophrenia. Data from the experimental and clinical literature suggest a basal ganglionic role in higher cognitive processes, affect, and attention. Deficits of these same factors serve to characterize the major symptoms of schizophrenia. Moreover, psychiatric patients tend to have frank motor problems characteristic of basal ganglia lesions and pathological conditions of the basal ganglia manifest psychiatric difficulties as a major symptom. Taken together, these data are in accord with the hypothesis that some dysfunction involving the basal ganglia is a major factor in schizophrenia.

Affect↗
PubMed1978

Trigeminal influences on entopeduncular units.

Because considerable work has implicated the basal ganglia in oral-ingestive behavior, an assessment was made of the effects of trigeminal stimuli upon entopeduncular single units. Units wre recorded extracellularly in awake, paralyzed and locally anesthetized cats. The effects of two types of sensory input were tested. Afferents from periodontal mechano-receptors involved in reflex jaw opening were stimulated via electrodes in the inferior dental nerve. Afferents from stretch receptors involved in reflex jaw closure were stimulated via electrodes in the trigeminal mesencephalic nucleus. A significant proportion of cells responded to both types of stimulation. The data were discussed in the context of a basal ganglionic role in oropharyngeal motor processes and a more general role in movement per se.

Afferent Pathways↗
PubMed1975

Pallidal and entopeduncular single unit activity in cats during drinking.

It has been shown that pallidal units display changes in firing rate during food seeking and consummatory behavior. The purpose of the present work was to determine which properties of the ingested material or ingestive behavior were most potent in altering unit activity. Single unit activity was recorded in the globus pallidus and entopeduncular nucleus of awake restrained cats during introduction of fluid into the mouth. A very high proportion of pallidal and entopeduncular neurons showed changes in firing rate during fluid injection. Two patterns of response were observed. Typically, responses were phasic and time-locked to the occurrence of fluid presentation. Less frequently, a long lasting change in firing occurred which persisted throughout the period of fluid introduction. Additional observations indicated that both of these changes in firing rate seemed to be related to the sensory rather than the motor aspects of ingestion.

Action Potentials↗
PubMed1975

Effects of hippocampal stimulation on acquisition, extinction and generalization of conditioned suppression in the rat.

Rats implanted with electrodes in the dorsal or ventral hippocampus received posttrial stimulation in training sessions with footshock reinforcement. Afterdischarges without overt seizures were consistently without effect on the rate of acquisition of suppression of licking during an auditory conditioned stimulus (CS), although conditioning was retarded by the delivery of distracting stimuli following footshock. The rate of conditioning remained insensitive to elicitation of dorsal hippocampal afterdischarges (DHAD) despite subsequent alterations of session length, intertrial interval and preexposure to the CS. However, faster extinction of suppression occurred following DHAD, suggesting a limited but essential role of the hippocampus in addressing stored information.

Acoustic Stimulation↗
PubMedDate not supplied

The effects of stimulation of trigeminal sensory afferents upon caudate units in cats.

This investigation assessed the influences of trigeminal primary sensory afferents upon caudate neuronal activity in locally anesthetized and chloralose anesthetized cats. Afferents from jaw elevator stretch receptors were stimulated via electrodes in the trigeminal mesencephalic nucleus (Mes 5). Afferents from dental and periodontal receptors were stimulated via electrodes in the inferior dental nerve (IDN). Low intensity electrical stimulation of either locus evoked caudate neuronal responses with Mes 5 being more effective. Higher intensity stimulation of IDN in chloralose anesthetized cats was used to determine if thresholds of trigeminal evoked caudate responses corresponded to thresholds of particular fiber groups in the sensory afferent. In all tested units, neuronal responses were only evoked when stimulation was suprathreshold for both A beta and A delta fibers. These data were discussed in relation to processing of oropharyngeal sensory information within the basal ganglia. Possible implications for bucco-lingual dyskinesias were noted.

Afferent Pathways↗