A chemical released by a presynaptic element upon stimulation that activates postsynaptic receptors.
Name five specific criteria in order to be a NT.
– It is synthesized in neuron
– It is present in the presynaptic terminal and is released in amounts sufficient to exert a defined action on the postsynaptic neuron
– When administered exogenously (as a drug) in reasonable concentrations, it mimics the action of the endogenous neurotransmitter exactly
– A specific mechanism exists for removing it from its site of action (the synaptic cleft) – dopamine transporter
What are the two main classes of neurotransmitters. Breifly describe them.
Small molecule neurotransmitters
What mental disorders involve DA dysfunction?
Parkinson’s disease: an age-related degenerative condition causing tremor and motor impairment, is caused by loss of dopamine-secreting neurons in the substantia nigra.
Schizophrenia: involves elevated levels of dopamine activity in the mesolimbic pathway and decreased levels of dopamine in the prefrontal cortex
Attention deficit hyperactivity
disorder (ADHD): associated with decreased dopamine activity.
Addiction: drugs of abuse (cocaine, amphetamine, opiates, and nicotine) act as positive reinforcers. They increase the level of DA released at terminals of the projections of the ventral tegmental area (VTA). Cocaine and amphetamine do so by blocking the DA transporter
What brain regions are involved in DA normal function in schizophrenia?
What brain regions are involved in DA dysfunction in schizophrenia?
Describe four major behavioral abnormalities of autism and tests in mice that can be used to examine those.
What is the role of amygdala in autistic behaviors? Which behaviors?
Which genes/biochemical pathways are involved or can be potentially involved in autism?