Behavioural genetics

Influence of gene action across different time scales on behavior.Ben-Shahar, Y. et al. Science 296, 741–744 (2002)

Different alleles of the foraging gene (for) in Drosophila cause flies to be either 'rovers' (foraging over a wide area) or 'sitters' (feeding more locally). Ben-Shahar et al. show that increased expression of the same gene is associated with the age-related transition from hive work to foraging in honeybees. The for gene encodes a cyclic-GMP-dependent protein kinase (PKG), and the authors found that increasing PKG activity could increase precocious foraging.

Addiction

Psychostimulant-induced behavioral sensitization depends on nicotinic receptor activation.Schoffelmeer, A. N. M. et al. J. Neurosci. 22, 3269–3276 (2002)

The authors found that repeated exposure to nicotine enhanced the psychomotor effects of amphetamine, and that nicotinic antagonists prevented the development of amphetamine- and cocaine-induced behavioural sensitization. Nicotinic antagonists also prevented the increase in dopamine release that was found in the nucleus accumbens after treatment with the psychostimulant drugs. The results indicate that nicotine might enhance the long-term effects of amphetamine and cocaine, and alter their addictive properties.

Neurological diseases

Gene-microarray analysis of multiple sclerosis lesions yields new targets validated in autoimmune encephalomyelitis.Lock, C. et al. Nature Med. 8, 500–508 (2002)

Lock et al. compared the gene expression profiles of 'active' and 'silent' multiple sclerosis (MS) lesions to identify genes that are expressed at different stages of the disease. Several genes that were differentially expressed had not previously been associated with MS. By modulating the expression of two of these genes, the authors reversed the symptoms of EAE (experimental allergic encephalomyelitis), a mouse model of MS. This approach might help in the development of therapies to treat specific aspects of MS.

Psychiatric disorders

Small intestinal enteropathy with epithelial IgG and complement deposition in children with regressive autism.Torrente, F. et al. Mol. Psychiatry 7, 375–382 (2002)

The authors describe a systematic study of lymphocytic colitis in children with regressive autism, comparing duodenal biopsies from these individuals with those from both normal and disease control groups. Their findings confirm the presence of a new form of enteropathy in autistic children, including increases in mucosal lymphocyte density, crypt cell proliferation, and epithelial deposition of IgG with complement C1q. They point to a possible autoimmune lesion in regressive autism.