Name the 2 main mechanisms by which glutamate is removed from the synaptic cleft.
diffusion into the presynaptic nerve terminal
uptake by glial cells (astrocytes)
Briefly describe uptake of glutamate by the glial cell.
Glutamate is taken into the astrocyte by a glutamate transporter. It is converted into glutamine by glutamine synthetase and then sent to the presynaptic nerve terminal by glutamine transporters. It undergoes reactions in the presynaptic nerve terminals to be converted back to glutamate.
ACh acts on _____ receptors in salivary, lacrimal, and other exocrine glands to _____ fluid and enzyme secretion.
ACh acts on _____ receptors in smooth muscle cells in gut walls, iris, ciliary body, bronchiolar muscle and bladder to _____ contraction.
ACh acts on _____ and _____ receptors in cerebral cortex and hippocampus to produce excitatory responses.
ACh acts on _____ receptors in cerebral cortex and hippocampus to produce inhibitory responses.
Most actions of ACh in brain are at _____ receptors. However, _____ receptors are found in terminals of the "brain reward circuit."
Describe how postganglionic cholinergic neurons stimulate exocrine glands and smooth muscle contraction.
Noradrenaline acts on _____ receptors in the heart to promote enhanced heart rate and contraction.
Catecholamines act on _____ receptors in bronchioles to promote relaxation of smooth muscle.
Why does acetylcholine affect heart rate but not the strength of contraction?
Postganglionic fibers do not end on the ventricles--only on the pacemaker.
How does noradrenaline affect the heart in comparison to acetylcholine?
Both increase heart rate, but only noradrenaline increases contractility.
Sympathetic neurons release _____ onto sweat glands. There are _____ receptors in the secretory cells.
Dopaminergic neurons in the _____ make projections on the hippocampus, nucleus accumbens and frontal lobe. They are responsible for _____.
D1 receptors are _____ receptors that facilitate rise in cAMP. This is associated with excitation.
What type of drugs are administered for Parkinson's disease?
Dopamine agonists on D2 (and D1) receptors in the basal ganglia
What type of drugs are used to treat psychosis?
drugs acting as dopamine antagonists on D2 receptors in forebrain
_____ and _____ bind to sites on subunits of GABA receptor and enhance inhibitory response caused by GABA binding to receptor sites. This leads to inhibition of cells in the _____.
Cholinergic, noradrenergic, and serotonergic neurons in the _____ and _____ make widespread projections to the thalamus and cortex to mediate arousal.
Noradrenergic and serotonergic neurons in the _____ make projections to the limbic lobe and cortex to mediate mood.
Name 2 types of drugs used to treat clinical depression.
selective serotonin re-uptake inhibitors (SSRIs)
Name the disorder: unilateral lesion in pathway between hypothalamus and cervical ganglion.