Prepared by Grant McLaren, Department of Psychology, Edinboro University of Pennsylvania FOUNDATIONS OF BEHAVIORAL NEUROSCIENCE 9 TH EDITION This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmission of any image over a network, preparation of any derivative work, including the extraction, in whole or in part, of any images, any rental, lease or lending of the program Copyright © 2014 Pearson Education, Inc. All Rights Reserved

Chapter 4 Psychopharmacology Copyright © 2014 Pearson Education, Inc. All Rights Reserved

Psychopharmacology psychopharmacology The study of the effects of drugs on the nervous system and on behavior. drug effect The changes a drug produces in an animal’s physiological processes and behavior. site of action A location at which molecules of drugs interact with molecules located on or in cells of the body, thus affecting some biochemical processes of these cells. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

Sites of Drug Action antagonist A drug that opposes or inhibits the effects of a particular neurotransmitter on the postsynaptic cell. agonist A drug that facilitates the effects of a particular neurotransmitter on the postsynaptic cell. Copyright © 2014 Pearson Education, Inc. All Rights Reserved

Principles of Psychopharmacology The first step is the synthesis of the neurotransmitter from its precursors. In some cases the rate of synthesis and release of a neurotransmitter is increased when a precursor is administered; in these cases the precursor itself serves as an agonist. (See step 1 in Figure 4.4.) Copyright © 2014 Pearson Education, Inc. All Rights Reserved Effects on Production of Neurotransmitters

Principles of Psychopharmacology The steps in the synthesis of neurotransmitters are controlled by enzymes. Therefore, if a drug inactivates one of these enzymes, it will prevent the neurotransmitter from being produced. Such a drug serves as an antagonist. (See step 2 in Figure 4.4.) Copyright © 2014 Pearson Education, Inc. All Rights Reserved Effects on Production of Neurotransmitters

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Neurotransmitters and Neuromodulators Acetylcholine is the primary neurotransmitter secreted by efferent axons of the central nervous system. All muscular movement is accomplished by the release of acetylcholine, and ACh is also found in the ganglia of the autonomic nervous system and at the target organs of the parasympathetic branch of the ANS. Three systems have received the most attention from neuroscientists: those originating in the dorsolateral pons, the basal forebrain, and the medial septum. Copyright © 2014 Pearson Education, Inc. All Rights Reserved Acetylcholine

Neurotransmitters and Neuromodulators The acetylcholinergic neurons located in the dorsolateral pons play a role in REM sleep (the phase of sleep during which dreaming occurs). Those located in the basal forebrain are involved in activating the cerebral cortex and facilitating learning, especially perceptual learning. Those located in the medial septum control the electrical rhythms of the hippocampus and modulate its functions, which include the formation of particular kinds of memories. Copyright © 2014 Pearson Education, Inc. All Rights Reserved Acetylcholine

Neurotransmitters and Neuromodulators botulinum toxin (bot you lin um) An acetylcholine antagonist; prevents release by terminal buttons. black widow spider venom A poison produced by the black widow spider that triggers the release of acetylcholine. Copyright © 2014 Pearson Education, Inc. All Rights Reserved Acetylcholine

Neurotransmitters and Neuromodulators Copyright © 2014 Pearson Education, Inc. All Rights Reserved Dopamine dopamine (DA) (dope a meen) A neurotransmitter; one of the catecholamines. L-DOPA (ell dope a) The levorotatory form of DOPA; the precursor of the catecholamines; often used to treat Parkinson’s disease because of its effect as a dopamine agonist.

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Neurotransmitters and Neuromodulators Copyright © 2014 Pearson Education, Inc. All Rights Reserved Dopamine nigrostriatal system (nigh grow stry ay tul) A system of neurons originating in the substantia nigra and terminating in the neostriatum (caudate nucleus and putamen). mesolimbic system (mee zo lim bik) A system of dopaminergic neurons originating in the ventral tegmental area and terminating in the nucleus accumbens, amygdala, and hippocampus.

Neurotransmitters and Neuromodulators Copyright © 2014 Pearson Education, Inc. All Rights Reserved Dopamine mesocortical system (mee zo kor ti kul) A system of dopaminergic neurons originating in the ventral tegmental area and terminating in the prefrontal cortex.

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Neurotransmitters and Neuromodulators Copyright © 2014 Pearson Education, Inc. All Rights Reserved Dopamine Parkinson’s disease A neurological disease characterized by tremors, rigidity of the limbs, poor balance, and difficulty in initiating movements; caused by degeneration of the nigrostriatal system.

Neurotransmitters and Neuromodulators Copyright © 2014 Pearson Education, Inc. All Rights Reserved Serotonin The third monoamine neurotransmitter, serotonin (also called 5- HT, or 5-hydroxytryptamine), has also received much experimental attention. serotonin (5-HT) (sair a toe nin) An indolamine neurotransmitter; also called 5- hydroxytryptamine. PCPA A drug that inhibits the activity of tryptophan hydroxylase and thus interferes with the synthesis of 5-HT.

Neurotransmitters and Neuromodulators Copyright © 2014 Pearson Education, Inc. All Rights Reserved Serotonin fluoxetine (floo ox i teen) A drug that inhibits the reuptake of 5-HT. fenfluramine (fen fluor i meen) A drug that stimulates the release of 5-HT.

Neurotransmitters and Neuromodulators Copyright © 2014 Pearson Education, Inc. All Rights Reserved Serotonin LSD A drug that stimulates 5-HT 2A receptors. MDMA A drug that serves as a noradrenergic and serotonergic agonist, also known as “ecstasy”; has excitatory and hallucinogenic effects.

Neurotransmitters and Neuromodulators Copyright © 2014 Pearson Education, Inc. All Rights Reserved Amino Acids GABA An amino acid; the most important inhibitory neurotransmitter in the brain. allylglycine A drug that inhibits the activity of GAD and thus blocks the synthesis of GABA. muscimol (musk i mawl) A direct agonist for the GABA binding site on the GABA A receptor.