During development, activity-dependent processes increase the specificity of neural responses to stimuli, but the role that this type of process plays in adult plasticity is unclear. We examined the dynamics of hippocampal activity as animals learned about new environments to understand how neural selectivity changes with experience. Hippocampal principal neurons fire when the animal is located...

We performed a stereological analysis of neuron number, neuronal soma size, and volume of individual regions and layers of the macaque monkey hippocampal formation during early postnatal development. We found a protracted period of neuron addition in the dentate gyrus throughout the first postnatal year and a concomitant late maturation of the granule cell population and individual dentate gyru...

BACKGROUND The level of expression of functional α7-containing nicotinic acetylcholine receptors (nAChRs) in hippocampal CA1 pyramidal neurons is believed to be very low compared to hippocampal CA1 interneurons, and for many years this expression was largely overlooked. However, high densities of expression of functional α7-containing nAChRs in CA1 pyramidal neurons may not be necessary for tri...

temporal lobe epilepsy (tle) is a disorder of the central nervous system in which hippocampus is mostly involved and causes memory impairment. kindling is a model of inducing epilepsy which is created through pentylenetetrazol (ptz) administration. this study examines the role of the aqueous extract of boswellia on the learning and development of brain (formation of dendritic branches and axons...

BACKGROUND While most patients with mild cognitive impairment (MCI) transition to Alzheimer disease (AD), others develop non-AD dementia, remain in the MCI state, or improve. OBJECTIVE To test the following hypotheses: smaller hippocampal volumes predict conversion of MCI to AD, whereas larger hippocampal volumes predict cognitive stability and/or improvement; and patients with MCI who conver...

Chronic exposure to opiates impairs hippocampal long-term potentiation (LTP) and spatial memory, but the underlying mechanisms remain to be elucidated. Given the well known effects of adenosine, an important neuromodulator, on hippocampal neuronal excitability and synaptic plasticity, we investigated the potential effect of changes in adenosine concentrations on chronic morphine treatment-induc...

The cornu ammonis 1 region of the hippocampus (CA1) sector of hippocampus is vulnerable to both Alzheimer's disease (AD)-type neurofibrillary degeneration and anoxia-ischemia. The objective of this article is to compare number and size of neurons in CA1 in AD versus ischemic vascular dementia. Unbiased stereological methods were used to estimate the number and volume of neurons in 28 autopsy-de...

Hippocampal μ-opioid receptors (MOR) have been implicated in memory formation associated with opiate drug abuse. MORs modulate hippocampal synaptic plasticity acutely, when chronically activated, and during drug withdrawal. At the network level, MORs increase excitability in area CA1 by disinhibiting pyramidal cells. The precise inhibitory interneuron subtypes affected by MOR activation are unk...

Hippocampal mu-opioid receptors (MORs) have been implicated in memory formation associated with opiate drug abuse. MORs modulate hippocampal synaptic plasticity acutely, when chronically activated, and during drug withdrawal. At the network level, MORs increase excitability in area CA1 by disinhibiting pyramidal cells. The precise inhibitory interneuron subtypes affected by MOR activation are u...

Antidepressants are drugs that relieve symptoms of depressive disorders. Fluoxetine, tianeptine, and milnacipran are different types of antidepressants, and they have widely been used for relieving of depression symptoms. In the present study, the effects of fluoxetine, tianeptine, and milnacipran on the glycine-induced ion current by nystatin-perforated patch clamp and on the amplitude of fiel...