Sex diff's in anxiety disorders

Question 1

Explain the intrinsic sex differences in
BNST neurons (4)

Answer 1

• Implicated in long term fear paradigms (evolution)
• Implicated in disease
• Women 2x as likely as men to develop
  PTSD
• Type II - Anxiety inhibiting

Question 2

Explain BNST pathway (3 +1)

Answer 2

Acts as a relay between neurological stressors and
hormone responses

upregs HPA axis
1) PFC, Amygdala + ventral subiculum -> BNST

2) Glu/Gaba

3) HPA = increased cortisol

Question 3

What are the cell types in the BNST? (3)

Answer 3

characterised by electrophysiological properties

• Type 1
  – Regular spiking
  – Sag (amount of deflection)
• Type II
  – Sag
  – Rebound firing
  – Hump on depolarising step
  – Anxiety inhibiting

Type III
-No sag
-CRF
-Anxiety inducing

Question 4

No sex-specific anxiety in unstressed rodent (1)

Answer 4

• darker and brighter circle maze: anxious hide in darker bits

Question 5

Passive membrane properties (type II cells) b/w sexes (4)

Answer 5

All characterisations of BNST cells done in males

• lower input resistance in females
• higher sag in females

= selection bias

Question 6

Firing properties (type II neurons) diff’s (3)

Answer 6

• females had decreasing firing
• needed more injected hyperpolarised current to fire
• increased latency to fire

Question 7

Correlation between behaviour and anxiety (2)

Answer 7

clear correlation for males: time spent in open arms = less anxious

not transferable to females

Question 8

Why is science male biased? (3)

Answer 8

• Oestrous cycle
• Visual methods
• vaginal smear
  = more expensive

4x the amount of work

Question 9

Cell signalling diff eg (2)

Answer 9

CRF r
- in males: beta-arrestin - internalise following acute stress

-in females: Gs pathway - limited sensitivity to b-arrestin = DO NOT internalise following acute stress

Question 10

Sex-specific effects in behaviour eg’s (4)

Answer 10

• high vs lower arousal
• stress controllability vs no effect
• anxiety vs prosocial behaviour
• recall same response but diff circuit

Question 11

Conclusion (3)

Answer 11

• The neuronal circuitry involved in stress and anxiety is sex-specific
• These can be differences in intrinsic properties, cell signalling pathways or cell regions involved
• Studying in females can be more expensive