Dopamine neurotransmission in the dorsal hippocampus is critical for a range of functions from spatial learning and synaptic plasticity to the deficits underlying psychiatric disorders such as attention-deficit hyperactivity disorder. The ventral tegmental area (VTA) is the presumed source of dopamine in the dorsal hippocampus. However, there is a surprising scarcity of VTA dopamine axons in th...

The septal and temporal poles of the hippocampus differ markedly in their anatomical and neurochemical organization. Although it is well established that the internal representation of space is a fundamental function of hippocampal neurons, most of what is known about spatial coding in the hippocampus of freely moving animals has come from recordings from the dorsal one-third (largely for techn...

In recent studies, inactivation of the dorsal hippocampus before the retrieval of extinguished fear memories disrupted the context-dependent expression of these memories. In the present experiments, we examined the role of the dorsal hippocampus in the acquisition of extinction. After pairing an auditory conditional stimulus (CS) with an aversive footshock [unconditional stimulus (US)], rats re...

The effect of excitotoxic lesions of dorsal vs. ventral hippocampus on the acquisition and expression of auditory trace fear conditioning was examined in two studies. In Experiment 1, animals received excitotoxic lesions of either the dorsal or ventral hippocampus or sham surgeries one week prior to conditioning, and were tested 24 h later. In Experiment 2, animals received excitotoxic lesions ...

One literature treats the hippocampus as a purely cognitive structure involved in memory; another treats it as a regulator of emotion whose dysfunction leads to psychopathology. We review behavioral, anatomical, and gene expression studies that together support a functional segmentation into three hippocampal compartments: dorsal, intermediate, and ventral. The dorsal hippocampus, which corresp...

Background and Objectives: Studies have documented the morhplogical, neurochemical and functional difference between the dorsal and ventral zones of hippocampus. The aim of this study was to assess the effects of chronic diabetes mellitus type1 on ventral and dorsal zones of hippocampus. Methods: Experimental diabetes was induced by stereptozotocin at a dose of 60 mg/kg. At the end of 8 weeks t...

The role of the hippocampus in pavlovian fear conditioning is controversial. Although lesion and pharmacological inactivation studies have suggested a key role for the dorsal hippocampus in contextual fear conditioning, the involvement of the ventral part is still uncertain. Likewise, the debate is open with regard to the putative implication of each hippocampal subdivision in fear conditioning...

Results: The anxiety indices of the traumatized rats were markedly higher than those of the controls (p<0.05). GluN1 and calmodulin levels were decreased in the dorsal hippocampus and amygdaloid complex of the traumatized rats. NOS expression increased significantly in both the amygdaloid complex and dorsal hippocampus where the increase was statistically more prominent in the amygdaloid comple...

The role of the hippocampus in memory is commonly investigated by comparing fear conditioning paradigms that differ in their reliance on the hippocampus. For example, the dorsal (septal) portion of the hippocampus is involved in trace, but not delay fear conditioning, two Pavlovian paradigms in which only the relative timing of stimulus presentation is varied. However, a growing literature impl...

Spatial scaling of place specific activity in the hippocampus varies systematically from the septal pole (high resolution) to the temporal pole (low resolution). Place fields get progressively larger, and the probability of observing a field in a given environment gets progressively smaller. It was previously found that decoupling movement in space from ambulation, by having the animal actively...