Neurotoxicity and dysfunction of dopaminergic systems associated with AIDS dementia

Mice expressing human mutant presenilin-1 exhibit decreased activation of NF-kappaB p50 in hippocampal neurons after injury

Mutations in the presenilin-1 (mutPS-1) gene, a cause of familial Alzheimer's disease, increase the susceptibility of neurons to apoptotic death. Using the trimethyltin model of hippocampal neurodegeneration, mice expressing the human mutPS-1 gene (M146L) exhibited increased neurodegeneration and mortality relative to non-transgenic littermates. Activation of NF-kappaB p50 was found to be impaired in transgenic mice with unaltered expression levels suggesting that mutPS-1 expression inhibits p50 activation to adversely affect neuronal resistance to injury.

Endogenous opiates: 2000

This paper is the twenty-third installment of the annual review of research concerning the opiate system. It summarizes papers published during 2000 that studied the behavioral effects of the opiate peptides and antagonists, excluding the purely analgesic effects, although stress-induced analgesia is included. The specific topics covered this year include stress; tolerance and dependence; learning, memory, and reward; eating and drinking; alcohol and other drugs of abuse; sexual activity, pregnancy, and development; mental illness and mood; seizures and other neurological disorders; electrical-related activity; general activity and locomotion; gastrointestinal, renal, and hepatic function; cardiovascular responses; respiration and thermoregulation; and immunological responses.

Induction of nuclear factor-kappaB in nucleus accumbens by chronic cocaine administration

DeltaFosB is a Fos family transcription factor that is induced by chronic exposure to cocaine and other drugs of abuse in the nucleus accumbens and related striatal regions, brain regions that are important for the behavioral effects of these drugs. To better understand the mechanisms by which DeltaFosB contributes to the effects of chronic drug treatment, we used DNA microarray analysis to identify genes that are regulated in the nucleus accumbens upon DeltaFosB expression in inducible bitransgenic mice. One of the most highly regulated genes was that encoding a subunit of another transcription factor, nuclear factor-kappaB (NF-kappaB). Subsequent experiments confirmed the induction of NF-kappaB in the nucleus accumbens of mice overexpressing DeltaFosB as well as in wild-type mice treated chronically, but not acutely, with cocaine. These results establish NF-kappaB as a putative target for DeltaFosB and implicate NF-kappaB signaling pathways in the long-term adaptations of nucleus accumbens neurons to cocaine.