CENTRAL INTEGRATIVE SYSTEMS

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CENTRAL INTEGRATIVE SYSTEMS

• D. C. MIKULECKY
• PROFESSOR OF PHYSIOLOGY
• AND
• FACULTY MENTORING PROGRAM

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BODY RHYTHMS AND THE HYPOTHALAMUS

• CIRCADIAN RHYTHMS AND BIOLOGICAL CLOCKS
• SLEEP

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CIRCADIAN RHYTHMS AND BIOLOGICAL CLOCKS

• OVER 100 BODY FUNCTIONS VARY ON A 24-HOUR
  SCHEDULE
• THYROXIN SECRETION CONTROLLED BY THE HYPOTHALAMUS
• ALSO ACTH AND CORTISONE
• MASTER CLOCK SUPRACHIASMATIC NUCLEUS OF THE
  HYPOTHALAMUS

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MANIFESTATIONS OF DAILY RHYTHMS

• BODY TEMPERATURE VARIATION
• DISRUPTION CAUSES PROBLEMS JET LAG

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SLEEP

• SLEEP HAS DIFFERENT STAGES
• NEURAL MECHANISMS OF SLEEP
• SLEEP DISORDERS

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SLEEP HAS DIFFERENT STAGES

• 3 TO 5 CYCLES PER NIGHT CONSISTING OF 5 STAGES
  (I - V AND REM)
• SLEEP STAGES BASED ON EEG ACTIVITY
• RAPID EYE MOVEMENT (REM) SLEEP
• SLEEP PATTERNS VARY WITH AGE

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3 TO 5 CYCLES PER NIGHT CONSISTING OF 5 STAGES
(I - V AND REM)

• FREQUENCY OF ELECTRICAL ACTIVITY DECREASES AS
  AMPLITUDE INCREASES
• BY STAGE 4 HEART RATE AND BLOOD PRESSURE HAVE
  DECREASED WHILE GI MOTILITY INCREASES
  (PARASYMPATHETIC ACTIVITY)
• REM SLEEP TAKES THE BRAIN FROM STAGE 4 BACK TO
  STAGE 1 (SYMPATHETIC ACTIVITY)
• REM SLEEP IS ASSOCIATED WITH VISUAL DREAMING

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SLEEP PATTERNS VARY WITH AGE

• WITH AGE TOTAL SLEEP TIME DECREASES
• ALSO THE REM SLEEP
• ALSO THE TIME SPENT IN STAGE 4

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NEURAL MECHANISMS OF SLEEP

• THE HYPOTHALAMUS AND BRAIN STEM ARE RESPONSIBLE
  FOR SLEEP/AWAKE CYCLES
• THE PREOPTIC AREA OF THE HYPOTHALAMUS INDUCES
  NON-REM SLEEP
• SEROTONON WILL ALSO INDUCE SLEEP WHEN INJECTED
  INTO THIS AREA
• RAPHE NUCLEUS MAY BE THE GENERATOR OF REM SLEEP

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SLEEP DISORDERS

• INSOMNIA INABILITY TO SLEEP, MAY BE CAUSED BY
  DISRUPTION OF CIRCADIAN RHYTHMS.
• NARCOLEPSY ATTACKS OF SLEEP AT ANY TIME, MAY BE
  DUE TO RAPHE NUCLEUS REM-SLEEP GENERATOR. AN
  INHERITED DISORDER. TREATED WITH AMPHETAMINES

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MOTIVATIONAL SYSTEMS

• HUNGER
• THIRST
• SEXUAL BEHAVIOR

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HUNGER
GLUCOSE RECEPTORS IN HYPOTHALAMUS
REDUCED AVAILABILITY OF GLUCOSE
SHORT TERM
MECHANO- RECEPTORS IN STOMACH
CONTRACTIONS OF EMPTY STOMACH
HUNGER
LACK OF FOOD
LOW TRIGLYCERIDE LEVELS IN FAT CELLS
LONG TERM
PANCREAS
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THIRST
OSMORECEPTORS IN SUPRAOPTIC AND
SUPRA- VENTRICULAR NUCLEI OF HYPOTHALAMUS
THIRST
WATER DEFICIENCY
WATER RETENTION BY KIDNEY
ADH SERETION BY PITUITARY
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SEXUAL BEHAVIOR

• ANTERIOR HYPOTHALAMUS ORGANIZES RESPONSES TO
  PHERMONES
• OLIFACTORY CUES SENT TO PYRIFORM CORTEX AND
  AMYGDALA AND INDIRECTLY TO HYPOTHALAMUS
• ANDROGENS DETERMINE RELEASE OF LEUTINIZING
  HORMONE- CONSTANT OR CYCLIC

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LEARNING AND MEMORY

• ASSOSCIATIVE VS NONASSOCIATIVE LEARNING
• SHORT AND LONG TERM MEMORY
• NEURONAL PATHWAYS
• SPLIT BRAIN STUDIES
• CELLULAR MANIFESTATIONS
• USE AND DISUSE

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ASSOSCIATIVE VS NONASSOCIATIVE LEARNING

• HABITUATION AND SENSITIZATION ARE NONASSOCIATIVE
• CLASSICAL CONDITIONING IS ASSOCIATIVE
• OPERANT CONDITIONING IS ASSOCIATIVE

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CONDITIONED REFLEX
RESPONSE CLOSE EYE
RED NUCLEUS
STIMULUS AIR PUFF ON EYE
CEREBELLUM PURKINJE CELL
OLIVARY NUCLEUS
CLIMBING FIBER
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CONDITIONED REFLEX
CONDITIONING STIMULUS TONE
RESPONSE CLOSE EYE
RED NUCLEUS
COCHLEAR NUCLEUS
STIMULUS AIR PUFF ON EYE
CEREBELLUM PURKINJE CELL
OLIVARY NUCLEUS
PONTINE NUCLEUS
MOSSY FIBERS
CLIMBING FIBER
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CONDITIONED REFLEX
CONDITIONING STIMULUS TONE
RESPONSE CLOSE EYE
RED NUCLEUS
COCHLEAR NUCLEUS
CEREBELLUM PURKINJE CELL
PONTINE NUCLEUS
MOSSY FIBERS
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SHORT AND LONG TERM MEMORY

• SHORT-TERM MEMORY INVOLVES IMMEDIATE USE, IS
  EASILY DISRUPTED AND AND IS SHORT LIVED
• LONG-TERM MEMORY IS MORE STABLE
• INFORMATION IS PASSED FROM SHORT- TERM TO
  LONG-TERM MEMORY BY A PROCESS CALLED CONSOLIDATION

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NEURONAL PATHWAYS

• MEMORY CIRCUITS PROVIDE A SIMPLE EXPLANAION FOR
  MEMORY
• THESE INVOLVE THE HYPOTHALAMUS AND AMYGDALA AS
  WELL AS THE TEMPORAL LOBE AND THE HIPPOCAMPUS

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SPLIT BRAIN STUDIES

• INFORMATION IS PROCESSED AND STORED DIFFERENTLY
  IN DIFFERENT SPECIES
• MONKEYS NEED BOTH HEMESPHERES WHILE CATS CAN
  LEARN IN ONE HEMISPHERE AND TRANSFER THE
  INFORMATION TO THE OTHER

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CELLULAR MANIFESTATIONS

• HABITUATION IS A DECREASE IN SYNAPTIC
  TRAQNSMISSION IN RESPONSE TO A REPEATED STIMULUS
• SENSITIZATION INVOLVES AN INCREASE IN TRANSMITTER
  RELEASE
• CLASSICAL CONDITIONING IS A SENSITIZATION PROCESS

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USE AND DISUSE

• IN EXERCISE MUSCLES INCREASE MASS WITH USE
• NEURAL PATHWAYS CAN STRENGTHEN OR WEAKEN
  CONNECTIONS BETWEEN NERVE CELLS
• THE OPPOSITE ALSO HAPPENS ATROPHY WITH DISUSE

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LANGUAGE SYSTEMS

• DOMINANT AND NONDOMINANT HEMISPHERES
• ANATOMICAL CORRELATES OF SPEECH DISORDERS

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LOCALIZATION OF LANGUAGE FUNCTIONS
ASSOCIATION
COMPREHENSION
MOTOR PROGRAMS
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DOMINANT AND NONDOMINANT HEMISPHERES

• TYPICALLY, SPEECH AREA IN DOMINANT HEMISPHERE IS
  LARGER
• THIS DIFFERENCE APPEARS IN THE HUMAN FETUS BY THE
  31ST WEEK OF GESTATION
• NONDOMINANT HEMISPHERE IS RESPONSIBLE FOR
  INTONATION AND EMOTIONAL ASPECTS

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ANATOMICAL CORRELATES OF SPEECH DISORDERS

• NONDOMINANT CORRELATE OF WERNICKES AND BROCAS
  AREAS APROSODIAS-INABILITY TO UNDERSTAND OR
  EXPRESS INTONATION
• APHASIAS LANGUAGE DISORDER DUE TO BRAIN DAMAGE
• DYSLEXIA CONGENITAL DISORDER AFFECTING READING

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APHASIAS

• BROCAS DISRUPTION OF MOTOR CENTERS-AFFECTS BOTH
  SPEECH AND WRITING
• WERNICKES AREA LOSS OF COMPREHENSION

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LATERALITY OF BRAIN FUNCTION

• RIGHT AND LEFT BRAIN
• GENDER DIFFERENCES

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RIGHT AND LEFT BRAIN

• RIGHT HEMISPHERE SPATIAL ABILITIES, ARTISTIC AND
  MUSICAL ABILITY
• LEFT HEMISPHERE ANALYTICAL SKILLS

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GENDER DIFFERENCES

• MALES TEND TO EXHIBIT MORE LATERALIZATION OF
  SPECIFIC TASKS
• FEMALES USE BOTH HEMISPHERES MORE SYMMETRICALLY