OVERVIEW

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OVERVIEW

• Neurotransmission
• Neurotransmitters
• Endocrine System
• Hormones
• Feedback Systems

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NEUROTRANSMISSION
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THE NEURON
Multipolar more than two processes from cell
body Unipolar one process from cell
body Bipolar two processes from cell
body Interneurons short or no axons Supportive
cells glial cells, satellite cells, astrocytes,
oligodendrocytes, Schwann cells
http//www.utexas.edu/research/asrec/synapse_m.htm
l
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COMMUNICATION.. cont
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COMMUNICATION

• Action potentials Ionic basis
• Conduction of Action Potentials
• Chemical Transmission at the Synapse

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ACTION POTENTIALS
mV millivolts
http//artsci-ccwin.concordia.ca/psychology/psyc35
8/Lectures/actpotent1.htm
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MEMBRANE POTENTIAL

• Random motion
• Electrostatic pressure
• Membrane permeability
• Sodium-potassium pumps

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http//web.psych.ualberta.ca/msnyder/Academic/Psy
ch104/ch6/lec2/P104.6.2.html
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When NTs bind to postsynaptic receptors

• Depolarize Excitatory Postsynaptic Potentials
  (EPSP)
• Hyperpolarize Inhibitory Postsynaptic Potentials
  (IPSP)
• Action potential reversal of membrane potential

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ACTION POTENTIALS
mV millivolts
http//artsci-ccwin.concordia.ca/psychology/psyc35
8/Lectures/actpotent1.htm
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http//luna.cas.usf.edu/husband/expsych/fig_axon.
htm
12
http//luna.cas.usf.edu/husband/expsych/fig_axon.
htm
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http//www.as.wvu.edu/rbrundage/chapter4a/sld028.
htm
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http//www.as.wvu.edu/rbrundage/chapter4a/sld028.
htm
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NEUROTRANSMITTERS HORMONES
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CHEMICAL COMMUNICATION

• Intracrine mediation intracellular
• Autocrine mediation feedback loops
• Paracrine mediation adjacent cells
• Endocrine mediation bloodstream
• Ecotcrine mediation pheromones

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HOW THEY DIFFER..

• NEUROTRANSMITTERS
• DF

• HORMONES
• KJH

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NEUROTRANSMITTERS
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STEPS OF NT ACTION

• Released NTs bind with autoreceptors and inhibit
  more release
• Released NTs bind to postsynaptic receptors
• Released NTs are deactived by reuptake or
  enzymatic degradation

• NTs are synthesized from precursors
• NTs are stored in vesicles
• Leaking NTs are destroyed
• Action potentials cause NTs to bind presynaptic
  membrane be released into synapse

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http//www.nipissingu.ca/saari/slides/pinel13/sld0
23.htm
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AGONISTIC EFFECTS

• Increases synthesis of NTs
• Destroys degrading enzymes
• Increases release of NTs
• Blocks inhibitory effects of NTs
• Activates postsynaptic receptors or increases
  effects of NTs
• Blocks degradation or reuptake

• Agonist drug that facilitates the effects of a
  particular neurotransmitter
• ex. Cocaine dopamine norepinephrine

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ANTAGONISTIC EFFECTS

• Blocks synthesis of NTs
• Causes NTs to leak from vesicles to be
  destroyed by degrading enzymes
• Blocks release of NTs into synapse
• Activates autoreceptors inhibits NT release
• Blocks postsynaptic receptors

• Antagonist drug that inhibits the effects of a
  particular neurotransmitter
• ex. Curare cholinergic receptors

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UPREGULATION
Http//www.utexas.edu/research/asrec/dopamine.html
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DOWNREGULATION
Http//www.utexas.edu/research/asrec/dopamine.html
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CLASSES OF NTs
Glutamate Aspartate Glycine GABA
Amino Acids
Dopamine Epinephrine Norepinephrine
Catecholamines
Monoamines
Indolamines
Serotonin
Soluble Gases
Nitric Oxide Carbon Monoxide
Acetylcholine
Acetylcholine
Neuropeptides
Hormones
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Http/web.indstate.edu/thcme/mwking/aminoacidderiv
atives.htmtyrosine
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DOPAMINE

• found primarily in the limbic system, parts of
  the hypothalamus, the frontal cortex, and
  forebrain (basal ganglia)
• thought disorders
• motor disorders
• pleasure pain
• role in addiction

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http//www.nipissingu.ca/saari/slides/pinel13/sld0
33.htm
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SEROTONIN

• high concentrations in the brain stem and
  thalamus
• sleep/wake cycle
• sensory perception
• emotional behaviour depression, impulsive
  behaviour, aggression

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NOREPINEPHRINE

• high concentrations in the cortex and limbic
  system
• Also works as hormone
• respiration
• activity, stimulation, and arousal
• rate of metabolism

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http//www.nipissingu.ca/saari/slides/pinel13/sld0
30.htm
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ACETYLCHOLINE

• Major NT of the motor system
• found at neuromuscular junction
• Learning and Memory
• memory loss of Alzheimers patients
• Sleep
• Nicotinic and muscarinic receptors

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http//www.nipissingu.ca/saari/slides/pinel13/sld0
24.htm
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GABA/GLUTAMATE

• GABA inhibitory effects
• Glutamate excitatory effects
• scatter throughout the brain
• Unique because
• of synapses using G/G gt than any other NT
  combined
• important functions in the body, not only the
  brain

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THE ENDOCRINE SYSTEM
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GENERAL FEATURES..

• 1. Endocrine glands are ductless
• 2. Endocrine glands have a rich blood supply
• 3. Hormones are secreted into the bloodstream
• 4. Hormones can travel to every cell in the body
• 5. Hormone receptors are specific binding sites

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ENDOCRINE GLANDS

• Hypothalamus
• Pituitary Gland
• Thyroid Gland
• Pancreas
• Gastrointestinal Tract
• Adrenal Glands
• Pineal Gland
• Gonads Testes Ovaries
• Placenta

http//www.ama-assn.org/ama/pub/printcat/7157.html
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(No Transcript)
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biological clock
STI MULI
HYPOTHALAMUS
CRH GnRH GHRF TRH
MIF Somatostatin PIF
PRL GH MSH
ANTERIOR PITUITARY
ACTH
OTHER TISSUE
TSH
FSHLH
ADRENALS THYROID TESTIS
OVARIES
(Cortisol) (Thyroid H) (T)
(Estrogen)
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HYPOTHALAMUS

• Releasing hormones
• produced by various nuclei of the hypothalamus
• involuntary body functions
• many simple body functions

http//www.cwru.edu/dental/web/neuro/ghts.html
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PITUITARY GLAND
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THYROID GLAND

• Thyroglobulin converted to T3 T4
• almost all cells are target of THs
• calcitonin
• metabolic rate, growth development

TRH Thyroid-releasing hormone
http//www.vivo.colostate.edu/hbooks/pathphys/endo
crine/hypopit/tsh.html
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PANCREAS

• digestive enzymes
• islets secrete insulin glucagon
• release dependent on level of glucose in blood

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GASTROINTESTINAL

• hormones that aid with digestion
• gastrin
• enterokinin
• secretin
• cholecystokinin (CCK)
• glucose dependent insulinotropic hormone
• vasoactive

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ADRENAL GLAND
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PINEAL GLAND

• biological rhythms
• Melatonin
• receptors in SCN
• night
• reproduction, sleep
• Seasonal Affective Disorder

http//www.crystalinks.com/thirdeyepineal.html
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GONADS TESTES OVARIES

• TESTES
• produce sperm and androgens
• LH FSH

• OVARIES
• produce ova, estrogen, and progesterone
• LH FSH
• menstrual cycle

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HORMONES

• Grouped into 3 classes, based on structure
• steroids
• peptides
• amines

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STEROIDS
http//www.emc.maricopa.edu/faculty/farabee/BIOBK/
BioBookENDOCR.html
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HORMONES

• Grouped into 3 classes, based on structure
• steroids
• peptides
• amines
• Mechanisms
• Nonsteroid second messenger systems
• Steroid hormone-receptor complex, DNA, protein
  production

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ESTROGEN

• released by ovary
• controlled/controls feedback
• sexual behaviour, maternal behaviour, menstrual
  cycle
• memory neurogenesis

http//www.vivo.colostate.edu/hbooks/pathphys/endo
crine/hypopit/lhfsh.html
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PROGESTERONE

• produced by ovaries
• works in conjunction with estrogen
• menstrual cycle
• pregnancy
• maternal behaviour
• sexual behaviour

http//www.wisc.edu/ansci_repro/lec/lec_11/lec11fi
g.htmlfigure205
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FSH LH

• essential for reproduction
• Luteinizing Hormone stimulates secretion of sex
  steroids health of ovary
• Follicle-Stimulating Hormone maturation of
  ovarian follicles sperm production

http//www.vivo.colostate.edu/hbooks/pathphys/endo
crine/hypopit/lhfsh.html
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TESTOSTERONE

• maintains spermatogenesis
• act of skeletal muscle
• secondary sex characteristics
• reproductive behaviour
• aggression

http//www.vivo.colostate.edu/hbooks/pathphys/endo
crine/hypopit/lhfsh.html
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OXYTOCIN VASOPRESSIN

• Vasopressin antidiuretic hormone conserve
  water reproductive function social behaviour
• Oxytocin birth lactation anti-amnestic
  maternal behaviour, social behaviour
• Stress?

http//www.vivo.colostate.edu/hbooks/pathphys/endo
crine/hypopit/oxytocin.html
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NEUROPEPTIDE Y LEPTIN

• NPY
• regulation of circadian rhythms, sexual
  functioning, anxiety, stress response, feeding
  behaviour
• neuropeptide
• synthesized in arcuate nucleus

• LEPTIN
• appetite regulation?
• ob/ob mice leptin replacement
• decreases NPY expression

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PROLACTIN

• closely related to GH
• major target mammary glands
• many tissues contain receptors
• milk production
• reproductive behaviour
• immune function
• maternal behaviour

regulated by DA, TRH, GnRH, E
http//www.vivo.colostate.edu/hbooks/pathphys/endo
crine/hypopit/prolactin.html
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GROWTH HORMONE

• Direct effects target receptors in fat protein,
  lipid, carbohydrate metabolism
• Indirect effects mediated by insulin-like growth
  factor-1 (IGF-1) muscle bone growth

GHRH growth hormone-releasing hormone SS
somatostatin
http//www.vivo.colostate.edu/hbooks/pathphys/endo
crine/hypopit/gh.html
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http//www.vivo.colostate.edu/hbooks/pathphys/endo
crine/hypopit/anatomy.html
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HORMONES

• needed for the immediate onset of maternal
  behaviour
• progesterone
• estrogen
• prolactin
• oxytocin
• glucocorticoids

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THE HPA AXIS POSTIVE NEGATIVE FEEDBACK SYSTEMS
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(No Transcript)
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Brain here
Cingulate Cx.
Inferior Temporal Cx.
Frontal Cx.
Amygdala
Hippocampus
Septum
Hypothalamus
Pituitary Gland
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THE HPA AXIS
LIMBIC SYSTEM (Hippocampus)
ve
HYPOTHALAMUS
(Paraventricular Nucleus)
-ve
CRH
PITUITARY GLAND
(Anterior Pituitary)
ACTH
ADRENAL GLAND
Glucocorticoid
(Adrenal Cortex)
65
THE HPA AXIS
LIMBIC SYSTEM
ve
HYPOTHALAMUS
(Paraventricular Nucleus)
-ve
CRH
PITUITARY GLAND
(Anterior Pituitary)
ACTH
ADRENAL GLAND
Glucocorticoid
(Adrenal Cortex)
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INPUTS TO THE LIMBIC SYSTEM
Modality specific areas
Association areas
Frontal association areas Inferior temporal
association areas
Amygdala
Entorhinal cortex
Hippocampus
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THE HPA AXIS
LIMBIC SYSTEM (Hippocampus)
ve
HYPOTHALAMUS
-ve
CRH
PITUITARY GLAND
(Anterior Pituitary)
ACTH
ADRENAL GLAND
Glucocorticoid
(Adrenal Cortex)
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LIMBIC INPUTS TO THE HYPOTHALAMUS
SEPTUM
MEDIAL FOREBRAIN BUNDLE
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OTHER INPUTS

• MEDULLA via the nucleus solitarius
  (baroreceptor information)
• MIDBRAIN via the reticular formation directly
  and indirectly through the thalamus
  (chemoreceptor information)
• BRAINSTEM monoaminergic inputs (physiological
  stress)

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EFFECTS OF CRH (Corticotropin-Releasing Hormone)
Epi NE ACh 5-HT

• STRESS RESPONSE
• activity, aggression, food intake, fear,
  anxiety, sexual maternal behaviour
• metabolism circulation

ve
- ve
CRH GABA opioids GC
found in brainstem, midbrain, striatum,
hippocampus, cerebral cortex, spinal chord,
sympathetic ganglia, adrenal gland
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THE HPA AXIS
LIMBIC SYSTEM (Hippocampus)
ve
HYPOTHALAMUS
(Paraventricular Nucleus)
-ve
CRH
PITUITARY GLAND
ACTH
ADRENAL GLAND
Glucocorticoid
(Adrenal Cortex)
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EFFECTS OF ACTH (Adrenocorticotropic Hormone)

• STRESS RESPONSE
• attention, motivation, learning, memory
• aggression, grooming, sexual social behaviour
• neurotrophic?

ANTERIOR PITUITARY
POMC
ACTH
beta-lipotropin
beta-endorphin
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THE HPA AXIS
LIMBIC SYSTEM (Hippocampus)
ve
HYPOTHALAMUS
(Paraventricular Nucleus)
-ve
Specific Organs
CRH
PITUITARY GLAND
(Anterior Pituitary)
ACTH
ADRENAL GLAND
Glucocorticoid
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EFFECTS OF GLUCOCORTICOIDS

• STRESS RESPONSE
• heart rate, blood pressure, respiration,
  digestion, growth, reproduction, immune function
• learning, cognition, emotional response, other
  behaviours

• GC-R I II
• hippocampus, septum, hypothalamus, amygdala,
  nucleus tractus solitarius
• mobilizes energy resources for adaptation to
  stressor

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HIPPOCAMPUS

• Negative Feedback mechanism?
• Mineralocorticoid Glucocorticoid Receptors
  ratio
• Species differences
• Chronic Stress Neuronal Death
• lack of brain food

glutamate
BNST
GABA
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Endocrine-related problems

• Overproduction of a hormone
• Cushings Syndrome
• Underproduction of a hormone
• Diabetes
• Nonfunctional receptors that cause target cells
  to become insensitive to hormones
• Growth Hormone Insensitivity