Visualization using the immediate early gene Arc revealed sparser and more robust odor representations in the anterior piriform cortex of adult rats when odor was associated with water reward over 2-3 d. Rewarded odor "mixtures" resulted in rats responding to either component odor similarly, and, correspondingly, the odor representations became more similar as indexed by increased overlap in pi...

Seizure causes neuronal cell loss in both animal models and human epilepsy. To determine the contribution of apoptotic mechanisms to seizure-induced neuronal cell death, rat brains were examined for the occurrence of terminal deoxynucleotidyl transferase-mediated UTP nick end labeling (TUNEL)-positive nuclei after pilocarpine-induced seizure. Numerous TUNEL-positive cells were observed througho...

Recent studies with kindling and convulsant drug models of epilepsy suggest that the piriform (primary olfactory) cortex may be particularly susceptible to generation of epileptiform activity. The present study has examined the generation of interictal epileptiform events in the piriform cortex of kindled rats in vivo, taking advantage of special features of this system that facilitate physiolo...

The transitional zone between the ventral part of the piriform cortex and the anterior cortical nucleus of the amygdala, named the cortex-amygdala transition zone (CxA), shows two differential features that allow its identification as a particular structure. First, it receives dense cholinergic and dopaminergic innervations as compared to the adjacent piriform cortex and amygdala, and second, i...

Pyramidal cells in piriform cortex integrate sensory information from multiple olfactory bulb mitral and tufted (M/T) cells. However, whether M/T cells belonging to different olfactory bulb glomeruli converge onto individual cortical cells is unclear. Here we use calcium imaging in an olfactory bulb-cortex slice preparation to provide direct evidence that neurons in piriform cortex receive conv...

The neural circuits of the piriform cortex mediate field potential oscillations and complex functions related to integrating odor cues with behavior, affective states, and multisensory processing. Previous anatomical studies have established major neural pathways linking the piriform cortex to other cortical and subcortical regions and major glutamatergic and GABAergic neuronal subtypes within ...

Studies of patients with focal brain injury indicate that smell perception involves caudal orbitofrontal and medial temporal cortices, but a more precise functional organization has not been characterized. In addition, although it is believed that odors are potent triggers of emotion, support for an anatomical association is scant. We sought to define the neural substrates of human olfactory in...

Habituation is a form of non-associative memory that plays an important role in filtering stable or redundant inputs. The present study examines the contribution of habituation and cortical adaptation to odor-background segmentation. Segmentation of target odorants from background odorants is a fundamental computational requirement for the olfactory system. Recent electrophysiological data have...