Vasopressin

Question 1

AVP structure

Answer 1

nonapeptide with 1 internal disulphide bridge

Question 2

where is AVP produced

Answer 2

magnocellular cells (SON & PVN)

Question 3

what does AVP do to blood vessels

Answer 3

vasopressor agent
contracts blood vessels (anti-diuretic hormone ADH)

Question 4

how does AVP regulate plasma osmolarity

Answer 4

hyperosmotic plasma increases AVP to form concentrated urine
hypoosmotic plasma decreases AVP to form diluted urine

Question 5

what is normosmotic plasma

Answer 5

280-295 mOsM

Question 6

action of alcohol on AVP

Answer 6

inhibits AVP
forms hyperosmotic plasma

Question 7

how are aquaporins inserted into the tubule cell membrane

Answer 7

AVP released from peritubular capillary binds to V2 R on basolateral membrane
AC
cAMP
PKA
aquaporin inserted into apical membrane

Question 8

chemoreceptors monitoring blood

Answer 8

trigger AVP and thirst
organum vasculosum of the lamina terminalis - OVLT circumventricular (no BBB)

Question 9

AVP release

Answer 9

AVP released from axons and dendrites
PHASIC bursting (burst of depolarisation)
increased frequency means increased stimulus

Question 10

benefits of phasic activity

Answer 10

keep recruiting other AVP neurons to reduce hypoosmotic stimulus
allows prolonged AVP release

Question 11

what does hypertonic saline cause

Answer 11

increases plasma AVP
can be reversed by drinking

Question 12

what does failure of ADH activity cause

Answer 12

diabetes insipidus
head injury to pituitary stalk
Rat produces 20L of hypoosmotic urine a day

Question 13

what does diabetes insipidus cause

Answer 13

thirst
polydipsia
hypovolemia
decreased bp
tachycardia

Question 14

decreased bp in atrium, aortic arch, carotid sinus

Answer 14

AVP released
acts on V1 a R on vascular smooth muscle

Question 15

AVP vs OT firing patterns

Answer 15

OT - bursting synchronised - spike release
AVP - phasic recruitment - maintained release

Question 16

pair bonding in male and female prairie voles

Answer 16

females - AVP has no effect
males - AVP induces pair bonding acts on V1a R (high density in ventral forebrain)

Question 17

Gobrogge and Wang (2015) V1a R overexpression in meadow voles

Answer 17

increases time spent huddling

Question 18

old field mice vs deer mice

Answer 18

monogamous old field mice - mimic female parental care
polygamous deer mice - little/absent parental care

Question 19

AVP mRNA expression in deer mice

Answer 19

highly expressed in hypothalamus
high CNS AVP prevents parental care

Question 20

Bendesky et al., 2017

Answer 20

administer ICV AVP in old-field mice inhibits nest building

Question 21

super-region for maternal behaviours

Answer 21

MPOA & BNST (bed nucleus of the stria terminalis)

Question 22

AVP release in the amygdala vs PVN

Answer 22

central amygdala - aggressive behaviour
PVN - unaffected

Question 23

(Bosch et al., 2010) inject AVP-ant into MPOA/BNST

Answer 23

decreased maternal aggression
decreased no of attacks
decreased frequency of attacks
increases latency before attack

Question 24

AVP and OCD

Answer 24

CSF AVP correlates to OCD in children
increased V1a R expression in PVN of depressed patients
V1 a R KO causes less anxious behaviour

Question 25

ASD symptoms

Answer 25

deficits in social communication, interaction and repetitive behaviour

Question 26

(Parker et al., 2019)
phase II VANILLA trials

Answer 26

Balovaptan (V1a R antagonist)
significant improvement of ASD at high doses