STARTLE AND SENSORIMOTOR CORRELATES OF VENTRAL THALAMIC DOPAMINE AND GABA IN RODENTS

RECENT studies have implicated the thalamus as a possible site for neu roanatomical and neurochemical changes in schizophrenia. In the presen t study, we investigated thalamic neurochemical correlates of behavior s potentially linked to schizophrenia. Whole thalamic DOPAC levels wer e elevated in rats that had poor extinction of the acoustic startle re sponse. The dopamine agonist apomorphine microinjected into the ventro medial thalamus (VmT) disrupted prepulse inhibition of startle. Catale psy was induced by VmT microinjections of the GABA-A agonist muscimol. A previous study revealed attentional disturbances and suppression of frontal cortical metabolic activity after muscimol microinjections in to the mediodorsal thalamic nucleus. Together with recent findings of neuron cell loss and elevated DA levels in the thalamus of schizophren ics, these data suggest the involvement of disturbances of thalamic ne urotransmission in schizophrenia.