Presynaptic GABAA receptors modulate synaptic transmission in several areas of the CNS but are not known to have this action in the cerebral cortex. We report that GABAA receptor activation reduces hippocampal mossy fibers excitability but has the opposite effect when intracellular Cl- is experimentally elevated. Synaptically released GABA mimics the effect of exogenous agonists. GABAA receptor...

The hippocampal mossy fiber (MF) pathway originates from the dentate gyrus granule cells and provides a powerful excitatory synaptic drive to neurons in the dentate gyrus hilus and area CA3. Much of the early work on the MF pathway focused on its electrophysiological properties, and ability to drive CA3 pyramidal cell activity. Over the last ten years, however, a new focus on the synaptic inter...

We performed MR imaging deformation-based hippocampal shape analysis in a 28-year-old woman in whom status epilepticus developed after acute encephalitis. Hippocampal shape analysis revealed severe global bilateral hippocampal atrophy. Regional volume loss was most accentuated in the medial and lateral aspects of the hippocampal head; the loss was similar to shape changes in hippocampal scleros...

PURPOSE To investigate the distribution of MR findings in the hippocampus and amygdala in patients with hippocampal sclerosis. METHODS We blindly evaluated MR scans for atrophy and signal changes occurring in the amygdala, hippocampal head, hippocampal body, and hippocampal tail in 57 consecutive patients with hippocampal sclerosis proved by pathologic analysis. RESULTS Regional atrophy or ...

Preclinical models of Alzheimer's disease (AD) suggest that volumetric reductions in medial temporal lobe (MTL) structures manifest before clinical onset. AD polygenic risk scores (PRSs) are further linked to reduced MTL volumes (the hippocampus/amygdala); however, the relationship between PRS and specific subregions remains unclear. We determine AD-PRSs a large sample young participants (N = 7...

The degree of hippocampal dentation, a morphologic feature the inferior surface human hippocampus, has been positively associated with episodic memory performance in healthy adults. This study examined dentation children and adolescents. Cincinnati MR Imaging NeuroDevelopment (C-MIND) dataset was used to examine relationship between age 90 children, < 1 18 years old, using T1-weighted MPRAGE...

The intracerebroventricular (icv) injection of amyloid peptides (Aβ) models Alzheimer’s disease (AD) in mice, as typified by the onset within 15 days deficits memory and hippocampal long-term potentiation (LTP) that are prevented blockade adenosine A2A receptors (A2AR). Since A2AR overfunction is sufficient to trigger deficits, we tested if were upregulated synapses before support hypothesis co...

BACKGROUND AND PURPOSE Memory impairment after stroke is poorly understood as stroke rarely occurs in the hippocampus. Previous studies have observed smaller ipsilateral hippocampal volumes after stroke compared with controls. Possibly, these findings on macroscopic level are not the first occurrence of structural damage and are preceded by microscopic changes that may already be associated wit...

bria-fornix complex. In this study, the anterograde tracer Phaseolus vulgaris-leucoagglutinin (PHAL) was used to analyze the ultrastructure and topography of identified fiber tracts within the fimbria-fornix. Septo-hippocampal fibers are loosely distributed throughout the fimbria-fornix. Commissural fibers cross the midline in the ventral hippocampal commissure and form a tight fiber bundle in ...