Medial septal cholinergic neurons modulate isoflurane anesthesia.

Background: Cholinergic drugs are known to modulate the response of general anesthesia. However, the sensitivity of isoflurane or other volatile anesthetics after selective lesion of septal cholinergic neurons that project to the hippocampus is not known.

Methods: Male Long Evans rats had 192 immunoglobulin G-saporin infused into the medial septum (n = 10), in order to selectively lesion cholinergic neurons, whereas control, sham-lesioned rats were infused with saline (n = 12).

Septohippocampal GABAergic neurons mediate the altered behaviors induced by n-methyl-D-aspartate receptor antagonists.

We hypothesize that selective lesion of the septohippocampal GABAergic neurons suppresses the altered behaviors induced by an N-methyl-D-aspartate (NMDA) receptor antagonist, ketamine or MK-801. In addition, we hypothesize that septohippocampal GABAergic neurons generate an atropine-resistant theta rhythm that coexists with an atropine-sensitive theta rhythm in the hippocampus. Infusion of orexin-saporin (ore-SAP) into the medial septal area decreased parvalbumin-immunoreactive (GABAergic) neurons by ~80%, without significantly affecting choline-acetyltransferase-immunoreactive (cholinergic) neurons.

Vestibular stimulation enhances hippocampal long-term potentiation via activation of cholinergic septohippocampal cells.

Vestibular stimulation induced acetylcholine release in the hippocampus, and acetylcholine is known to facilitate long-term potentiation (LTP) in the hippocampus. Thus, we hypothesize that vestibular stimulation enhances LTP in CA1 in freely behaving rats, and this enhancement depends on the activation of septohippocampal cholinergic neurons. Field excitatory postsynaptic potentials were recorded in CA1 area of behaving rats following stimulation of the basal dendritic afferents.

Activation of immobility-related hippocampal theta by cholinergic septohippocampal neurons during vestibular stimulation.

The vestibular system has been suggested to participate in spatial navigation, a function ascribed to the hippocampus. Vestibular stimulation during spatial navigation activates a hippocampal theta rhythm (4-10 Hz), which may enhance spatial processing and motor response. We hypothesize that a cholinergic, atropine-sensitive theta is generated during passive whole-body rotation in freely behaving rats.

Ketamine-induced deficit of auditory gating in the hippocampus of rats is alleviated by medial septal inactivation and antipsychotic drugs.

Rationale: Gating of sensory responses is impaired in schizophrenic patients and animal models of schizophrenia. Ketamine, an N-methyl-D-aspartate receptor antagonist, is known to induce schizophrenic-like symptoms including sensory gating deficits in humans.

Objective: This study aims to investigate the mechanisms underlying ketamine's effect on gating of auditory evoked potentials in the hippocampus of freely moving rats.

Hippocampal theta state in relation to formalin nociception.

In the present study using extracellular electrophysiological recording techniques, we explored the temporal characteristics of hippocampal theta activation in relation to formalin nociception. Results indicate that, compared to hind paw injection of saline, formalin injection in behaving rat evoked biphasic increase in duration of dorsal CA1 theta. Such an increase broadly paralleled animal biphasic behavioral activation, especially lick and moment-to-moment agitated behaviors.

Differential expression of metallothionein 1 and 2 isoforms in breast cancer lines with different invasive potential: identification of a novel nonsilent metallothionein-1H mutant variant.

Metallothionein (MT), a low-molecular weight protein with pleiotropic functions, is believed to play an important role in tumorigenesis. The aim of this study was to compare the expression of functional MT-1 and MT-2 mRNA isoforms in five breast cancer cell lines ranging from noninvasive MCF7 breast cancer cells to highly aggressive MDA-MB-231 breast cancer cells together with breast myoepithelial cells in vitro by conventional semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and quantitative real-time RT-PCR. The MT-2A isoform was observed to be differentially upregulated in the invasive phenotype.