Available evidence suggests there is functional differentiation among hippocampal and parahippocampal subregions and along the dorsoventral (septotemporal) axis of the hippocampus. The aim of this study was to characterize and compare the efferent and afferent connections of perirhinal areas 35 and 36, postrhinal cortex, and the lateral and medial entorhinal areas (LEA and MEA) with dorsal and ...

The sources of ipsilateral projections from the hippocampal formation, the presubiculum, area 29a-c, and parasubiculum to medial, orbital, and lateral prefrontal cortices were studied with retrograde tracers in 27 rhesus monkeys. Labeled neurons within the hippocampal formation (CA1, CA1', prosubiculum, and subiculum) were found rostrally, although some were noted throughout the entire rostroca...

Early involvement of the hippocampal formation is the biological basis of the typical learning deficit in Alzheimer's disease (AD). However, the hippocampal formation is unevenly affected by AD pathology, deposits of plaques and tangles being particularly dense in the CA1 field and subiculum. The aim of the study was to locate in vivo the structural changes within the hippocampal formation in A...

The anterior thalamic nuclei are a vital node within hippocampal-diencephalic-cingulate circuits that support spatial learning and memory. Reflecting this interconnectivity, the overwhelming focus of research into cognitive functions has been processing. However, there is increasing evidence extend beyond realm. This work highlighted how these required for certain classes temporal discriminatio...

The hippocampal formation, one of the most complex and vulnerable brain structures, is recognized as a crucial brain area subserving human long-term memory. Yet, its specific functions in memory are controversial. Recent experimental results suggest that the hippocampal contribution to human memory is limited to episodic memory, novelty detection, semantic (deep) processing of information, and ...

The role of the hippocampal formation in learning and memory has long been recognized. However, despite decades of intensive research, the neurobiological basis of this process in the hippocampus remains enigmatic. Over 30 years ago, the production of new neurons was found to occur in the brains of adult rodents. More recently, the documentation of adult neurogenesis in the hippocampal formatio...

Clinical and experimental studies have shown that the hippocampal formation and related structures in the medial temporal lobe are important for learning and memory. Retrograde amnesia was studied prospectively in monkeys to understand the contribution of the hippocampal formation to memory function. Monkeys learned to discriminate 100 pairs of objects beginning 16, 12, 8, 4, and 2 weeks before...

introduction: lower level of estrogen hormone is considered as an important factor for loss of learning and memory in postmenopausal women. although estrogen replacement therapy is used for compensation, but long-term usage of estrogen is associated with a higher risk of hormonedependent cancers. phytoestrogens, due to fewer side effects, have been proposed to prevent menopause-related cognitiv...

We have previously shown that hippocampal long-term potentiation (LTP), one form of synaptic plasticity that may underlie learning and memory, is attenuated by blocking neuron activity of the basolateral amygdala (BLA). In the present study we investigated the amygdala noradrenergic or cholinergic contribution to hippocampal LTP formation. When propranolol, a beta-adrenoceptor antagonist, was i...

OBJECTIVE To rely on the anatomical organization of the hippocampal formation in understanding whether and how late-life diseases such as diabetes and stroke contribute to age-related cognitive decline. METHODS Magnetic resonance imaging (MRI) was used to document brain infarcts and to generate high-resolution functional maps of the hippocampal formation in 240 community-based nondemented eld...