Afferent projections of the infralimbic cortex (area 25) in rats: a WGA-HRP study

The afferent connections of the infralimbic area (area 25) of the medial prefrontal cortex in rats were studied using WGA-HRP as the tracer. The present results confirm previously reported afferent connections of the infralimbic area and further reveal additional inputs from the anterior amygdaloid area, anterior cortical amygdaloid nucleus, posterolateral cortical amygdaloid nucleus, ventral reunions, lateral preoptic area, dorsal hypothalamic area, posterior hypothalamic nucleus, supramammillary nucleus and medial mammillary nucleus. Only afferent projections were found from CA1 of the hippocampus and amygdalo-piriform transition area. The results also confirm extensive afferent connections of the infralimbic cortex from the central autonomic nuclei and, together with previous results on efferent connections of the infralimbic cortex, provide further support for an essential role of this nucleus as a cortical center of the autonomic nervous system.