These results show that UP states under ketamine anesthesia have a stable, fine-structured firing pattern despite a large variability in global structure. “
“Cerebellar coordination and Cognition Group, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands Most mammals possess a vomeronasal system that detects predominantly chemical signals of biological relevance. Vomeronasal information is relayed to the accessory olfactory bulb
(AOB), whose unique cortical target is the posteromedial cortical nucleus of the amygdala. This cortical structure should therefore be considered the primary vomeronasal cortex. In the present work, we describe the afferent and efferent connections of the posteromedial cortical nucleus of the amygdala in female
c-Met inhibitor mice, using anterograde (biotinylated dextranamines) and retrograde (Fluorogold) tracers, and zinc selenite as a tracer specific for zinc-enriched (putative glutamatergic) projections. The results show that the posteromedial cortical nucleus of the amygdala is strongly interconnected not only with the rest of the vomeronasal system (AOB and its target structures in the amygdala), but also with the olfactory system (piriform cortex, olfactory-recipient nuclei of the amygdala and entorhinal cortex). Therefore, the posteromedial cortical nucleus of the amygdala probably integrates olfactory and vomeronasal information. In addition, the posteromedial cortical nucleus of the amygdala shows moderate interconnections Suplatast tosilate with the associative (basomedial) amygdala and with the ventral hippocampus, which MAPK inhibitor may be involved in emotional and spatial learning
(respectively) induced by chemical signals. Finally, the posteromedial cortical nucleus of the amygdala gives rise to zinc-enriched projections to the ventrolateral septum and the ventromedial striatum (including the medial islands of Calleja). This pattern of intracortical connections (with the olfactory cortex and hippocampus, mainly) and cortico-striatal excitatory projections (with the olfactory tubercle and septum) is consistent with its proposed nature as the primary vomeronasal cortex. “
“The aim of this study was to examine the potential ability of neuronal groups to enhance their activities by conditioning without behaviors. We employed a method of neuronal operant conditioning in which increments in the firing rates and synchrony of closely neighboring neurons in the motor cortex and hippocampus were rewarded in the absence of behaviors. Rats were trained to engage in a free-operant task in which nose-poke behaviors were rewarded in session 1, and firing rates and synchrony above preset criteria were rewarded in sessions 2 and 3, respectively. The firing rates of motor cortical and hippocampal neuron groups were found to increase rapidly in session 2 similarly to the nose-poke behavior in session 1.