The projections to the retrosplenial cortex (areas 29 and 30) from the hippocampal formation, the entorhinal cortex, perirhinal cortex, and amygdala were examined in two species of macaque monkey by tracking the anterograde transport of amino acids. Hippocampal projections arose from the subiculum and presubiculum to terminate principally in area 29. Label was found in layer I and layer III(IV)...

The earliest stages of Alzheimer's disease (AD) are characterized by the formation of mature tangles in the entorhinal cortex and disorientation and confusion when navigating familiar places. The medial entorhinal cortex (MEC) contains specialized neurons called grid cells that form part of the spatial navigation system. Here we show in a transgenic mouse model expressing mutant human tau predo...

Pervasive Developmental Disorder (PDD) is a categorical term used to classify disorders in which the patient suffers deficits in three main domains: language, behavior and social skills. Heparin Binding Growth Associated Molecule (HB-GAM) is an extracellular protein involved in neurite outgrowth and radial migration. Mice deficient in HB-GAM demonstrate deficits in cognition, behavior and socia...

The hippocampus communicates with the neocortex via the entorhinal cortex. These areas are thought to be critically involved in the consolidation of memories. The hippocampus is considered to be the site of association of sensory information, which is then laid down for long-term storage in the neocortex. We examined the projection from the subiculum to the entorhinal cortex to determine whethe...

In vitro whole cell patch-clamp recordings of stellate cells in layer II of medial entorhinal cortex show a subthreshold membrane potential resonance in response to a sinusoidal current injection of varying frequency. Physiological recordings from awake behaving animals show that neurons in layer II medial entorhinal cortex, termed "grid cells," fire in a spatially selective manner such that ea...

To investigate the role of the entorhinal cortex in memory at a molecular level, we developed transgenic mice in which transgene expression was inducible and limited to the superficial layers of the medial entorhinal cortex, pre- and parasubiculum. We found that expression of a constitutively active mutant form of CaMKII in these structures disrupted spatial memory formation. Immediate post-tra...

The mammalian space circuit is known to contain several functionally specialized cell types, such as place cells in the hippocampus and grid cells, head-direction cells and border cells in the medial entorhinal cortex (MEC). The interaction between the entorhinal and hippocampal spatial representations is poorly understood, however. We have developed an optogenetic strategy to identify function...

The theta band oscillation in the hippocampus and medial entorhinal cortex carries a strong correlation with free movement throughout an environment. Recently several models of these oscillations and their relationship to spatially modulated cells in the hippocampus and entorhinal cortex have started to emerge. One area of focus in theta research has been how the speed of movement modulates the...

Three or four pairs of bipolar electrodes were chronically implanted in the hippocampal formation, subicular area, and entorhinal cortex of rats, all on the same side. The EEG, EOG, and neck EMG were also recorded. Responses due to electrical stimulation of one electrode pair were recorded in the other electrode pairs during slow-wave sleep, paradoxical sleep, and arousal. The stimuli were sing...

Performance on visual delayed nonmatching-to-sample was assessed in rhesus monkeys with combined and separate ablations of the perirhinal and entorhinal cortex, as well as in unoperated controls. Combined (i.e., rhinal cortex) lesions yielded a striking impairment on this task, one almost as severe as that seen after combined amygdalohippocampal removals that included some of this subjacent cor...