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TRANSCRIPT
Slide 1Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Bear: Neuroscience: Exploring the Brain 3e
Chapter 15: Chemical Control of the Brain and Behavior
Slide 2Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Introduction
Synaptic ConnectionsPoint-to-point
Mechanism to restrict synaptic communicationBrief transmissionPresynaptic “autoreceptors”
Three nervous system componentsSecretory hypothalamusAutonomic nervous system (ANS)Diffuse modulatory systems
Slide 3Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
The Secretory Hypothalamus
FunctionDifferent for hypothalamus and dorsal thalamus
Hypothalamus defectFatal disruption to body function
Dorsal thalamus defectBlind spot, lack of feeling
Slide 4Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
HomeostasisRegulatory process: Regulates body temperature and blood composition levels
Hypothalamus commands in cold weather
Shiver, goosebumps, turn blueHypothalamus commands in hot weather
Turn red, sweat
The Secretory Hypothalamus
Slide 5Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Structure and Connections of the Hypothalamus
The Secretory Hypothalamus
Slide 6Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Pathways to the Pituitary
Two neurohormonesOxytocin
Lactation, suppress hypothalamic function
VasopressinRegulate blood volume and salt concentration
The Secretory Hypothalamus
Slide 7Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Hypothalamic Control of the Posterior Pituitary
The Secretory Hypothalamus
Slide 8Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Hypothalamic Control of the Anterior Pituitary
Anterior lobeControlled by parvocellular neurosecretory cells
Secrete hypophysiotropic hormoneBind to specific receptors on pituitary cellsReceptor activation: Pituitary cells secrete or stop secreting hormones
Adrenal glands: Adrenal cortex and adrenal medulla
The Secretory Hypothalamus
Slide 9Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Divisions of autonomic nervous system (ANS)Sympathetic division
Increased heart rate and blood pressureDepressed digestive functionMobilized glucose reserves
Parasympathetic divisionSlower heart rate, fall in pressureIncreased digestive functionsStop sweating
The Autonomic Nervous System
Slide 10Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
ANS Circuits versus Somatic Motor System
ANSActions multiple, widespread, slowWide coordinated and graded controlCommands all tissue and organ except skeletal muscleOutside CNSDisynaptic pathway
The Autonomic Nervous System
Slide 11Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
The Autonomic Nervous System
ANS Circuits versus Somatic Motor System (Cont’d)
SomaticRapid and accurateOnly peripheral targetsCommands only skeletal muscleWithin CNSMonosynaptic pathway
Slide 12Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
The Autonomic Nervous System
Sympathetic and Parasympathetic Divisions
Slide 13Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
The Enteric DivisionLocation: Lining of esophagus, stomach, intestines, pancreas, and gallbladder Composition: Two complicated networks- myenteric (Auerbach's) plexus and submucous (Meissner's) plexus Function: Control physiological processes involved in transport, digestion of foodInputs: From brain via axons of the sympathetic and parasympathetic divisions
The Autonomic Nervous System
Slide 14Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Central Control of the ANSConnections for autonomic control
Periventricular zone connections to brain stem and spinal cord nucleiNucleus of solitary tract
Function of solitary nucleusIntegrates sensory information from internal organs and coordinates output
The Autonomic Nervous System
Slide 15Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Neurotransmitters and the Pharmacology of Autonomic Function
ANS: Better understanding of drug mechanisms influencing synaptic transmission (vs. CNS)
Preganglionic NeurotransmittersPrimary transmitter: AChACh: Binds to nAChR, evokes fast EPSPGanglionic ACh: Activates mAChR, slow EPSPs and IPSPsPreganglionic terminals: Small EPSPs
The Autonomic Nervous System
Slide 16Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Postganglionic NeurotransmittersParasympathetic: Release Ach
Local effectSympathetic: Release NE
Far-reaching effectsParasympathomimetic: Mimic or promote muscarinic actions of ACh or inhibit actions of NESympathomimetic: Mimic or promote NE actions or inhibit muscarinic actions of ACh
The Autonomic Nervous System
Slide 17Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Anatomy and FunctionsDifferent structure and function, common principles
Small set of neurons at coreArise from central core of brainOne neuron influences othersSynapses release transmitter molecules into extracellular fluid
The Diffuse Modulatory Systems of the Brain
Slide 18Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
The Nonadrenergic Locus CoeruleusPath: Axons innervate cerebral cortex, thalamus, hypothalamus, olfactory bulb, cerebellum, midbrain, spinal cordFunction: Regulation of attention, arousal, sleep-wake cycles, learning and memory, anxiety and pain, mood, brain metabolismActivation: New, unexpected, nonpainful sensory stimuli
The Diffuse Modulatory Systems of the Brain
Slide 19Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
The Serotonergic Raphe Nuclei
The Diffuse Modulatory Systems of the Brain
Slide 20Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Dopaminergic CellsSubstantia Nigra
Projects axons to the striatumFacilitates the initiation of voluntary movements
Ventral tegmental areaInnervates circumscribed region of telecephalon
Mesocorticolimbic dopamine system: Dopaminergic projection from midbrain
The Diffuse Modulatory Systems of the Brain
Slide 21Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Cholinergic SystemsBasal forebrain complex
Core of telencephalon, medial and ventral to basal gangliaFunction: Unknown, participates in learning and memory
Pontomesencephalotegmental complexReleases AChFunction: Regulates excitability of thalamic sensory relay nuclei
The Diffuse Modulatory Systems of the Brain
Slide 22Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Drugs and the Diffuse Modulatory Systems
Psychoactive drugs: Act on CNSMany drugs of abuse act on modulatory systems
NoradrenergicDopaminergicSerotonergic
The Diffuse Modulatory Systems of the Brain
Slide 23Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
HallucinogensLSD discovery: Accidentally by Swiss chemist Albert HofmannLSD chemical structure: Close to serotonin, potent agonistEffect: Dreamlike state, mixing of perceptions – cortical areas
The Diffuse Modulatory Systems of the Brain
Slide 24Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Stimulants
The Diffuse Modulatory Systems of the Brain
Slide 25Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
Concluding Remarks
Three Components of the Nervous System That Have Great Reach of Their Influences
Secretory hypothalamus (all over the body)Autonomic nervous system (all over the body)Diffuse modulatory systems (all over the brain)
Detailed level Each system performs different functions
General levelAll work to maintain brain homeostasis
Slide 26Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams
& Wilkins
End of Presentation