chemical control of brain & behaviour

Question 1

what are the forms of communication?

Answer 1

1) direct synaptic transmission
2) diffuse modulatory systems
3) neuroendocrine signaling
4) autonomic nervous system networks

Question 2

what do the diffuse modulatory systems do?

Answer 2

coordinate activation of groups of neurons in broad brain regions

Question 3

where does DMS originate from?
what does DMS activate?

Answer 3

• core neurons (small set, only several thousand)
• originate from brainstem nuclei
• activate CNS metabrotropic receptors
• synapse NT release, but also NT release into extracellular fluid

Question 4

what does the noradrenergic system origin?

Answer 4

locus coeruleus

Question 5

noradrenergic system projections?

Answer 5

cortex, thalamus, cerebellum

Question 6

noradrenergic system purpose? 6

Answer 6

• attention
• arousal
• sleep wake cylce
• attentive tasks

responds to most new, unexpected stimuli
increases neuron responsiveness

Question 7

serotonergic system origin?

Answer 7

raphe nuclei

Question 8

serotonergic system projections?

Answer 8

forebrain

Question 9

serotonergic system purpose? 3

Answer 9

acts as locus with NE system
- modulates sleep/wake cycle
- fires more during wakefulness
- fires least during sleep

mood control
- selective seretonin reuptake inhibitors combat depression

activates and deactivates forebrain

Question 10

dopaminergic (substantia nigra) system origin?

Answer 10

substantia nigra

Question 11

dopaminergic (substantia nigra) projections?

Answer 11

projects to the striatum (caudate and putamen)

Question 11

dopaminergic (substantia nigra) purpose?

Answer 11

voluntary movement initiation

Question 12

dopaminergic (mesocorticolimbic) origin?

Answer 12

ventral tegmental area

Question 13

dopaminergic (mesocorticolimbic) projections?

Answer 13

• frontal cortex
• limbic system

Question 14

dopaminergic (mesocorticolimbic) purpose?

Answer 14

reward system that reinforces behaviours

Question 15

basal cholinergic system origin?

Answer 15

telencephalon

Question 16

basal cholinergic system projections?

Answer 16

• basal nucleus of mynert -> neocortex
• medial septal nuclei -> hippocampus

Question 17

basal cholinergic system function?

Answer 17

• learning and memory
• coordinate activity in large brain areas
• first area that degenerates with alzeheimers

Question 18

ponto cholinergic system origin?

Answer 18

• pons
• tegmentum

Question 19

ponto cholinergic system projections?

Answer 19

• thalamus
• telencephalon

Question 20

ponto cholinergic system purpose?

Answer 20

• dorsal thalamus: regulate excitability of sensory relay nuclei
• telencephalon: ACh link between brainstem and basal forebrain complex
• ANS: neuromuscular junction

Question 21

what are stimulants that effect the diffuse modulatory system?

Answer 21

cocaine and meth

Question 22

what do cocaine and meth do?

Answer 22

cocaine
- blocks DA reuptake

meth
- blocks catecholamine reuptake, stimulates DA release

Question 23

what is the effect of NE/DA reuptake being blocked?

Answer 23

emotional
- increases alertness and self-confidence, euphoria, decreased appetite, exhilaration

physical
- mimic sympathetic activation: increase heart rate and blood pressure, pupil dilation

Question 24

what does the neuroendocrine system do?

Answer 24

cells in the periventricular hypothalamus coordinate neuroendocrine signaling - communicates w/ body - helps regulate ANS outflow and circadian rythyms - contains neurosecretory neurons that send axons to the pitutary for hormone signaling helos maintain homeostasis - integrates different signals to drive behaviour - signals (hormones, somatic, etc)

Question 25

what does the neuroendocrine system connect to?

Answer 25

pituitary gland

Question 26

what does the neuroendocrine contain?

Answer 26

- posterior pituitary - anterior pituitary - hypothalamus-pituitary adrenal axis/HPA axis - HPA axis and the Hippocampus

Question 27

what differentiates prairie voles from montane voles?

Answer 27

prairie voles - monogamus - have oxytocin and vasopressin receptors, in the brains reward areas montane voles - polygamous - become monagomus when injected with oxytocin and vasopressin

Question 28

how is the anterior pituitary different from the posterior pituitary?

Answer 28

posterior does not release hormones directly in the blood stream, amplifies signal for other cells to do that

Question 29

what does the anterior pituitary do?

Answer 29

involved with the release of other hormones

Question 30

what does the HPA axis do?

Answer 30

mediator of stress response, involves the anterior pituitary hormone cortisol

Question 31

what does the feedback loop in the HPA axis do?

Answer 31

negative feedback loop - inhibits CRH and ACTH release

Question 32

what are the negative effects of chronic stress?

Answer 32

baboons low in the social heirarchy have higher stress which leads to higher cortisol without regulation higher cortisol can lead to - hypertension, ulcers, depression

Question 33

what is the function of the autonomic nervous system?

Answer 33

commands every non-skeletal muscle - smooth muscle - cardiac - gland

Question 34

how does the ANS differ from somatic motor control?

Answer 34

somatic motor control is monosynaptic ans is disynaptic

Question 35

describe sANS - where are its pre-synaptic fiber located? - where do the fibers originate?

Answer 35

sympathetic : fight or flight - presynaptic fibers synapse in ganglia close to spinal cord - originate in thoracic and lumbar segments

Question 36

describe pANS - where are the presynaptic fibers located? - where do they originate?

Answer 36

parasympathetic: rest and digest - presynaptic fibers synapse in ganglia closer to target tissue - originate in brainstem and sacral segment

Question 37

what does the enteric division do?

Answer 37

functions relatively independently in the gastrointestinal system, works w/ viscera

Question 38

where does the enteric division get its input? what is it made up of?

Answer 38

- gets some input from ANS - made up of neurons that line the gut

Question 39

at do enterochromaffin cells do?

Answer 39

communicate gut info to the brain - the gut has taste receptors similar to the toungt