M1 muscarinic receptor for the development of auditory cortical function.

The sensory cortex is subject to continuous remodelling during early development and throughout adulthood. This process is important for establishing normal brain function and is dependent on cholinergic modulation via muscarinic receptors. Five muscarinic receptor genes encode five unique receptor subtypes (M1-5). The distributions and functions of each subtype vary in central and peripheral systems. In the brain, the M1 receptor is most abundant in the cerebral cortex, where its immunoreactivity peaks transiently during early development. This likely signifies the importance of M1 receptor in the development and maintenance of normal cortical function. Several lines of study have outlined the roles of M1 receptors in the development and plasticity of the auditory cortex. For example, M1-knockout reduces experience-dependent plasticity and disrupts tonotopic mapping in the adult mouse auditory cortex. Further evidence demonstrates a role for M1 in neurite outgrowth and hence determining the structure of cortical neurons. The disruption of tonotopic maps in M1-knockout mice may be linked to alterations in thalamocortical connectivity, because the targets of thalamocortical afferents (layer IV cortical neurons) appear less mature in M1 knockouts. Herein we review the literature to date concerning M1 receptors in the auditory cortex and consider some future directions that will contribute to our understanding.

Prevalence of non-organ-specific autoantibodies in patients with pemphigus vulgaris.

BACKGROUND: Pemphigus vulgaris (PV) is a potentially life-threatening, organ-specific, autoimmune, blistering disease of the skin and mucous membranes. Although several reports suggest an association between pemphigus and other autoimmune connective tissue disorders, studies that measure non-organ-specific autoantibodies are lacking. OBJECTIVE: To evaluate the prevalence of antinuclear antibodies (ANA), anti-double-stranded DNA (anti-dsDNA) antibodies, and antibodies against extractable nuclear antigens (ENAs) in PV patients. METHODS: Serum samples were obtained from 59 PV patients and 50 healthy controls. Indirect immunofluorescence assays containing human epithelial cell substrates (HEp-2) and Crithidia luciliae were used to detect ANA and anti-dsDNA antibodies, respectively. A multiplexed addressable laser bead immunoassay was employed to measure autoantibodies to: Smith (Sm), ribonucleoprotein (RNP), Sjögren syndrome B (SSB/La), Sjögren syndrome A (SSA/Ro), histidyl transfer ribonucleic acid synthetase (Jo-1), topoisomerase I (Scl-70), and ribosome-P (Ribo-P) antigens. RESULTS: Positive ANAs were obtained in 22 of 59 (37.3%) PV patients compared with 4 of 50 (8.0%) healthy controls (p