The Role of Central Monoaminergic Systems in Arousal and Selective Attention
Annual technical rept. 1 Apr 1989-31 Mar 1990
HAHNEMANN MEDICAL COLL AND HOSPITAL PHILADELPHIA PA DEPT OF PHYSIOLOGY AND BIOPHYSICS
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The work described here is part of an ongoing set of studies aimed at characterizing the physiological actions and anatomical organization of the monoaminergic projection systems to the rat cerebral cortex. The underlying theme of this work is that the endogenous monoamines, norepinephrine NE and serotonin 5-HT, serve to modulate central neuronal responsiveness to afferent synaptic inputs and by so doing participate in the cognitive process of selective attention. Individual studies conducted during the past year have investigated 1 the adrenergic and amino acid receptor specificity of NE- induced facilitation of glutamate efficacy, 2 the influence of NE on GABA- induced membrane conductance changes in identified cortical neurons, 3 the effects of NE on the receptive field properties of visual cortical neurons and 4 the anatomical distribution of monoamine-containing cells that project via axon collaterals to multiple sites along the central somatosensory pathway. Overall, the data provide further support for the contention that the diffusely distributed monoamine systems of the mammalian brain may enhance the performance of target neuronal circuits as a function of changing behavioral conditions.