Diabetic neuropathic pain, an important micro vascular complication in diabetes mellitus, has been recognized as one of the most difficult types of pain to treat. Lack of understanding of etiology involved, inadequate relief, development of tolerance and potential toxicity of classical anti-nociceptive agents warrants the investigation of newer agents to relieve this pain. The aim of the presen...

Altered serotonin indices have been reported in the brain of suicide victims. We sought to localize the changes in presynaptic and postsynaptic serotonin receptors and identify an area of prefrontal cortex that may influence suicide risk. Quantitative autoradiography was performed in coronal sections of prefrontal cortex to determine whether serotonin 5-HT1A receptor (postsynaptic in cortex) an...

UNLABELLED 4,2'-(Methoxyphenyl)-1-[2'-(N-2"-pyridinyl)-p-fluorobenzamido]ethylpiperazine ((18)F-MPPF) is a radiotracer used in clinical PET studies for the visualization of serotonin-1A (5-HT(1A)) receptors. In a previous study, we demonstrated that a rapid enhancement of extracellular serotonin concentrations influences (18)F-MPPF-specific binding. Because endogenous serotonin is significantly...

Maintenance of energy balance requires regulation of the amount and timing of food intake. Decades of experiments utilizing pharmacological and later genetic manipulations have demonstrated the importance of serotonin signaling in this regulation. Much progress has been made in recent years in understanding how central nervous system (CNS) serotonin systems acting through a diverse array of ser...

The basal ganglia (BG) play a critical role in the pathogenesis and pathophysiology of Parkinson’s disease (PD). Recent studies indicate that serotoninergic systems modulate BG activity, and may be implicated in the pathophysiology and treatment of PD. The globus pallidus (GP), the rodent homologue of the primate GPe, is the main central nucleus of the basal ganglia, affecting the striatum, the...

UNLABELLED Many inhaled anesthetics block the in vitro effect of the excitatory neurotransmitter serotonin on the 5-HT2A receptor, supporting the view that this receptor might mediate the capacity of inhaled anesthetics to produce immobility during noxious stimulation (i.e., would underlie MAC, the minimum alveolar concentration required to suppress movement in response to a noxious stimulus in...

The serotonin system in prefrontal cortex (PFC) is critically involved in the regulation of cognition and emotion. To understand the cellular mechanisms underlying its physiological actions, we investigated the role of serotonin in regulating synaptic plasticity in PFC circuits. We found that tetanic stimuli coupled to bath application of serotonin induced long-term depression (LTD) at excitato...

Egg-laying behavior in Caenorhabditis elegans is regulated by multiple neurotransmitters, including acetylcholine and serotonin. Agonists of nicotinic acetylcholine receptors such as nicotine and levamisole stimulate egg laying; however, the genetic and molecular basis for cholinergic neurotransmission in the egg-laying circuitry is not well understood. Here we describe the egg-laying phenotype...

BACKGROUND Cultured sensory neurons are a common experimental model to elucidate the molecular mechanisms of pain transduction typically involving activation of ATP-sensitive P2X or capsaicin-sensitive TRPV1 receptors. This applies also to trigeminal ganglion neurons that convey pain inputs from head tissues. Little is, however, known about the plasticity of these receptors on trigeminal neuron...