Alzheimer's Disease: An Attempt of Total Recall.

This review is an attempt to compile existing hypotheses on the mechanisms underlying the initiation and progression of Alzheimer's disease (AD), starting from sensory impairments observed in AD and concluding with molecular events that are typically associated with the disease. These events include spreading of amyloid plaques and tangles of hyperphosphorylated tau and formation of Hirano and Biondi bodies as well as the development of oxidative stress. We have detailed the degenerative changes that occur in several neuronal populations, including the cholinergic neurons in the nucleus basalis of Meynert, the histaminergic neurons in the tuberomammillary nucleus, the serotonergic neurons in the raphe nuclei, and the noradrenergic neurons in the locus coeruleus.

The Induction of Long-Term Potentiation by Medial Septum Activation under Urethane Anesthesia Can Alter Gene Expression in the Hippocampus.

We studied changes in the expression of early genes in hippocampal cells in response to stimulation of the dorsal medial septal area (dMSA), leading to long-term potentiation in the hippocampus. Rats under urethane anesthesia were implanted with stimulating electrodes in the ventral hippocampal commissure and dMSA and a recording electrode in the CA1 area of the hippocampus. We found that high-frequency stimulation (HFS) of the dMSA led to the induction of long-term potentiation in the synapses formed by the ventral hippocampal commissure on the hippocampal CA1 neurons.

Detailed Analysis of Dorsal-Ventral Gradients of Gene Expression in the Hippocampus of Adult Rats.

We performed RNA sequencing of the dorsal and ventral parts of the hippocampus and compared it with previously published data to determine the differences in the dorsoventral gradients of gene expression that may result from biological or technical variability. Our data suggest that the dorsal and ventral parts of the hippocampus differ in the expression of genes related to signaling pathways mediated by classical neurotransmitters (glutamate, GABA, monoamines, etc.) as well as peptide and Wnt ligands.

Deep Brain Stimulation of the Medial Septal Area Can Modulate Gene Expression in the Hippocampus of Rats under Urethane Anesthesia.

We studied the effects of stimulation of the medial septal area on the gene expression in the dorsal and ventral hippocampus. Rats under urethane anesthesia were implanted with a recording electrode in the right hippocampus and stimulating electrode in the dorsal medial septum (dMS) or medial septal nucleus (MSN). After one-hour-long deep brain stimulation, we collected ipsi- and contralateral dorsal and ventral hippocampi.

Intrahippocampal Adeno-Associated Virus-Mediated Overexpression of Nerve Growth Factor Reverses 192IgG-Saporin-Induced Impairments of Hippocampal Plasticity and Behavior.

One of the aspects of Alzheimer disease is loss of cholinergic neurons in the basal forebrain, which leads to development of cognitive impairment. Here, we used a model of cholinergic deficit caused by immunotoxin 192IgG-saporin to study possible beneficial effects of adeno-associated virus (AAV)-mediated overexpression of nerve growth factor (NGF) in the hippocampus of rats with cholinergic deficit. Suspension of recombinant AAV carrying control cassette or cassette with NGF was injected into both hippocampi of control rats or rats with cholinergic deficit induced by intraseptal injection of 192IgG-saporin.