A novel nicotinic acetylcholine receptor subtype in basal forebrain cholinergic neurons with high sensitivity to amyloid peptides.

Nicotinic acetylcholine receptors (nAChRs) containing alpha7 subunits are thought to assemble as homomers. alpha7-nAChR function has been implicated in learning and memory, and alterations of alpha7-nAChR have been found in patients with Alzheimer's disease (AD). Here we report findings consistent with a novel, naturally occurring nAChR subtype in rodent, basal forebrain cholinergic neurons.

GABA(A) receptor-mediated excitation in dissociated neurons from human hypothalamic hamartomas.

The cellular mechanisms underlying intrinsic epileptogenesis in human hypothalamic hamartoma (HH) are unknown. We previously reported that HH tissue is composed predominantly of GABAergic neurons, but how GABAergic-neuron-rich HH tissue is intrinsically epileptogenic is unclear. Here, we tested the hypotheses that some HH neurons exhibit immature features and that GABA excites these neurons via activation of GABA(A) receptors (GABA(A)Rs).

Electrophysiological properties and subunit composition of GABAA receptors in patients with gelastic seizures and hypothalamic hamartoma.

Abnormalities in GABA(A) receptor structure and/or function have been associated with various forms of epilepsy in both humans and animals. Whether this is true for patients with gelastic seizures and hypothalamic hamartoma (HH) is unknown. In this study, we characterized the pharmacological properties and native subunit composition of GABA(A) receptors on acutely dissociated single neurons from surgically resected HH tissues using patch-clamp, immunocytochemical, and RT-PCR techniques.

Iptakalim modulates ATP-sensitive K(+) channels in dopamine neurons from rat substantia nigra pars compacta.

Iptakalim, a novel cardiovascular ATP-sensitive K(+) (K(ATP)) channel opener, exerts neuroprotective effects on dopaminergic (DA) neurons against metabolic stress-induced neurotoxicity, but the mechanisms are largely unknown. Here, we examined the effects of iptakalim on functional K(ATP) channels in the plasma membrane (pm) and mitochondrial membrane using patch-clamp and fluorescence-imaging techniques. In identified DA neurons acutely dissociated from rat substantia nigra pars compacta (SNc), both the mitochondrial metabolic inhibitor rotenone and the sulfonylurea receptor subtype (SUR) 1-selective K(ATP) channel opener (KCO) diazoxide induced neuronal hyperpolarization and abolished action potential firing, but the SUR2B-selective KCO cromakalim exerted little effect, suggesting that functional K(ATP) channels in rat SNc DA neurons are mainly composed of SUR1.