An Excitant Amino Acid Projection from the Medial Prefrontal Cortex to the Anterior Part of Nucleus Accumbens in the Rat

Publisher Website
Google Scholar
Abstract
High-affinity uptake of neurotransmitter substrates in synaptosome-containing homogenates and tissue concentrations of amino acids were examined in subcortical areas 5-6 days after bilateral-N-methyl-D-aspartate lesions confined to rat medial prefrontal cortex. -D-[3H]Aspartate (32% of control) and [3h]GABA (60% of control) uptakes were significantly reduced in medial prefrontal cortex; [3H]choline (110% of control) uptake was unchanged, suggesting the production of axon-sparing lesions. The uptake of D-[3H]aspartate (76% of control), but not of [3H]GABA or [3H]choline, was significantly reduced in nucleus accumbens, with no concomitant reduction in amino acids concentrations. When examined in serial coronal sections, reduced D-[3H]aspartate uptake was confined to the most anterior 500 .mu.m of nucleus accumbens (67% of contralateral sample). No significant reductions of uptake or amino acid concentrations were observed in caudate putament or ventral tegmental area. These results suggest a role for glutamate or aspartate as neurotransmitters in projections from medial prefrontal cortex to anterior nucleus accumbens. Medial prefrontal cortex may represent the major excitatory cortical input to the nucleus accumbens.