| First Author | Lozada AF | Year | 2012 |
| Journal | J Neurosci | Volume | 32 |
| Issue | 24 | Pages | 8391-400 |
| PubMed ID | 22699919 | Mgi Jnum | J:185573 |
| Mgi Id | MGI:5429441 | Doi | 10.1523/JNEUROSCI.6247-11.2012 |
| Citation | Lozada AF, et al. (2012) Induction of Dendritic Spines by beta2-Containing Nicotinic Receptors. J Neurosci 32(24):8391-400 |
| abstractText | Glutamatergic synapses are located mostly on dendritic spines in the adult nervous system. The spines serve as postsynaptic compartments, containing components that mediate and control the synaptic signal. Early in development, when glutamatergic synapses are initially forming, waves of excitatory activity pass through many parts of the nervous system and are driven in part by a class of heteropentameric beta2-containing nicotinic acetylcholine receptors (beta2*-nAChRs). These beta2*-nAChRs are widely distributed and, when activated, can depolarize the membrane and elevate intracellular calcium levels in neurons. We show here that beta2*-nAChRs are essential for acquisition of normal numbers of dendritic spines during development. Mice constitutively lacking the beta2-nAChR gene have fewer dendritic spines than do age-matched wild-type mice at all times examined. Activation of beta2*-nAChRs by nicotine either in vivo or in organotypic slice culture quickly elevates the number of spines. RNA interference studies both in vivo and in organotypic culture demonstrate that the beta2*-nAChRs act in a cell-autonomous manner to increase the number of spines. The increase depends on intracellular calcium and activation of calcium, calmodulin-dependent protein kinase II. Absence of beta2*-nAChRs in vivo causes a disproportionate number of glutamatergic synapses to be localized on dendritic shafts, rather than on spines as occurs in wild type. This shift in synapse location is found both in the hippocampus and cortex, indicating the breadth of the effect. Because spine synapses differ from shaft synapses in their signaling capabilities, the shift observed is likely to have significant consequences for network function. |
