Hibernation is a potential protective strategy for the peripheral, as well as for the central nervous system. A protein factor termed hibernation induction trigger (HIT) was found to induce hibernation in summer-active ground squirrels. Purification of HIT yielded an 88-kD peptide that is enriched in winter hibernators. Partial sequence of the 88-kD protein indicates that it may be related to t...

BACKGROUND The mechanism of the antinociceptive effects of nitrous oxide (N(2)O) has not been completely elucidated. On the other hand, numerous studies have indicated that mesolimbic dopaminergic neurons, which are thought to be involved in rewarding and reinforcement processes, play important roles in the supraspinal pain-suppression system. We hypothesized that the mesolimbic dopaminergic sy...

It is believed that BALB/c mice appear to be less sensitive to the locomotor effects of abused drugs compared to other strains, and several behaviors induced by abused drugs depend on genetic factors. The present study was designed to investigate the effects of the interaction between psychostimulants and morphine on behavior in BALB/c mice. Morphine and cocaine induced hyperlocomotion and hypo...

Parkinson 's disease (PD) is characterized by progressive loss of dopaminergic neurons in the nigrostriatal pathway, but this seems to constitute only part of the whole pathological process of the disease. Accumulating data have documented the concomitant degeneration of other dopaminergic pathways and of the serotonergic, cholinergic and noradrenergic neurotransmitter systems. In addition,...

Parkinson's disease (PD) is characterized by the loss of dopamine-producing neurons in the nigrostriatal system. Numerous researchers in the past have attempted to track the progression of dopaminergic depletion in PD. We applied a quantitative non-invasive PET imaging technique to follow this degeneration process in an MPTP-induced mouse model of PD. The VMAT2 ligand (18)F-DTBZ (AV-133) was us...

Nicotine is the primary psychoactive substance in tobacco, and it exerts its effects by interaction with various subtypes of nicotinic acetylcholine receptors (nAChRs) in the brain. One of the major subtypes expressed in brain, the α4β2-nAChR, endogenously modulates neuronal excitability and thereby, modifies certain normal as well as nicotine-induced behaviors. Although α4-containing nAChRs ar...

Electrophysiological techniques were used to study the effects of amisulpride, a D2/D3 dopamine receptor blocker, on the activity of dopaminergic neurons in the substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA). Administration of single bolus doses of amisulpride (8-32 mg/kg i.v.) induced a dose-dependent increase in the basal activity of dopaminergic neurons, in both th...

The theory that alterations of dopaminergic synaptic transmission may play a role in the pathogenesis of schizophrenia is widely accepted. A more recent theory links the endorphin system to the etiology of schizophrenia. We propose that these two theories may be combined into a single model. Recent neurochemical and pharmacological findings have indicated close functional relationships between ...

Members of the natural resistance-associated macrophage protein (NRAMP) family are evolutionarily conserved metal ion transporters that play an essential role in regulating intracellular divalent cation homeostasis in both prokaryotes and eukaryotes. Malvolio (Mvl), the sole NRAMP family member in insects, plays a role in food choice behaviors in Drosophila and other species. However, the speci...

Schizophrenia is a highly heritable disorder, but the identification of specific genes has proven to be a difficult endeavor. Genes involved in the dopaminergic system are considered to be major candidates since the "dopamine hypothesis" of impairment in dopaminergic neurotransmission is one of the most widely accepted hypotheses of the etiology of schizophrenia. The overall findings from candi...