In a long-term longitudinal study of aging in rhesus monkeys, a primary objective has been to determine the effects of aging and caloric restriction (CR) on behavioral and neural parameters. Through the use of automated devices, locomotor activity can be monitored in the home cages of the monkeys. Studies completed thus far indicate a clear age-related decline in activity consistent with such observations in many other species, including humans. However, no consistent effects of CR on activity have been observed.
Addiction is a chronic and relapsing psychiatric disorder that is thought to occur in vulnerable individuals. Synaptic plasticity evoked by drugs of abuse in the so-called neuronal circuits of reward has been proposed to underlie behavioral adaptations that characterize addiction. By increasing dopamine in the striatum, addictive drugs alter the balance of dopamine and glutamate signals converging onto striatal medium-sized spiny neurons (MSNs) and activate intracellular events involved in long-term behavioral alterations.
Proceedings of the National Academy of Sciences of the United States of America
Recent studies have identified impairments in neural induction and in striatal and cortical neurogenesis in Huntington's disease (HD) knock-in mouse models and associated embryonic stem cell lines. However, the potential role of these developmental alterations for HD pathogenesis and progression is currently unknown. To address this issue, we used BACHD:CAG-Cre(ERT2) mice, which carry mutant huntingtin (mHtt) modified to harbor a floxed exon 1 containing the pathogenic polyglutamine expansion (Q97).
In previous functional magnetic resonance imaging (fMRI) studies concerning romantic love, several brain regions including the caudate and putamen have consistently been found to be more responsive to beloved-related than control stimuli. In those studies, infatuated individuals were typically instructed to passively view the stimuli or to think of the viewed person. In the current study, we examined how the instruction to attend to, or ignore the beloved modulates the response of these brain areas.
Changes in socio-emotional behavior and conduct, which are characteristic symptoms of frontal lobe damage, have less often been described in patients with focal subcortical injuries. We report on a case of pathological generosity secondary to a left lenticulocapsular stroke with hypoperfusion of several anatomically intact cortical areas. A 49-year-old man developed excessive and persistent generosity as he recovered from a left lenticulocapsular hematoma. His symptoms resembled an impulse control disorder.
How we are viewed by other individuals-our reputation-has a considerable influence on our everyday behaviors and is considered an important concept in explaining altruism, a uniquely human trait. Previously it has been proposed that processing one's own reputation requires a reputation representation in the medial prefrontal cortex (mPFC) and a value representation in the striatum. Here, we directly tested this idea using functional magnetic resonance imaging (fMRI).
Attention, suggestion, context and expectation can all exert top-down influence on bottom-up processes (e.g., stimulus-driven mechanisms). Identifying the functional neuroanatomy that subserves top-down influences on sensory information processing can unlock the neural substrates of how suggestion can modulate behavior. Using functional magnetic resonance imaging (fMRI), we scanned 10 healthy participants (five men) viewing five bistable figures. Participants received a directional cue to perceive a particular spatial orientation a few seconds before the bistable figure appeared.
RATIONALE: The transcription factor cAMP responsive element-binding protein 1 (CREB1) has a complex influence on behavioural responses to drugs of abuse which varies depending on the brain region in which it is expressed. In response to drug exposure, CREB1 is phosphorylated in the striatum, a structure that is critically involved in reward-related learning. OBJECTIVE: The present study assessed the role of striatal CREB1 and its coactivator CREB-binding protein (CBP) in behavioural responses to psychostimulants.
The effect of a standardized extract of Bacopa monniera Linn. was assessed on rat brain frontal cortical, striatal and hippocampal superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities, following administration for 7, 14 or 21 days. The effects induced by this extract (bacoside A content 82% +/- 0.5%), administered in doses of 5 and 10 mg/kg, orally, were compared with the effects induced by (-) deprenyl (2 mg/kg, p. o.) administered for the same time periods.
Central Nervous System Agents in Medicinal Chemistry
Withania somnifera (WS) an ayurvedic medicinal herb is widely known for its memory enhancing ability and improvement of brain function. In the present study, we tested the hypothesis that WS prophylaxis could offset neurotoxicant-induced oxidative dysfunctions in developing brain employing a rotenone (ROT) mouse model. Initially, we assessed the potential of WS oral supplements (100-400 mg/ kg b.w/ d, 4wks) to modulate the endogenous levels of oxidative markers in cerebellum (cb) and striatum (st) of prepubertal (PP) mice.