VASOPRESSIN-DEPENDENT NEURAL CIRCUITS UNDERLYING BOND FORMATION IN THE MONOGAMOUS PRAIRIE VOLE

LIM, MM AND YOUNG, LJ. NEUROSCIENCE, 2004.

Yvonne Pao November 7, 2008

Neural Control of Social Behaviors Seems to involve:

Arginine vasopressin (AVP) + V1a receptor (V1aR)

Reward circuitry: Ventral pallidum (VP) Mediodorsal thalamus (MDthal)

Medial amygdala Social memory formation Olfactory/somatosensory processing of

sociosexual stimuli Monogamous prairie voles have high

levels of V1aR in these structures

Hypothesis

Sociosexual and reward circuits underlie pair bond formation

Approach:1. Examine Fos induction in these circuits2. Block V1aR in specific structures3. Adeno-associated viral (AAV) vector gene

transfer to increase V1aR gene density in specific regions

Experiment 1: Fos Induction

Subjects: Sexually naïve male prairie voles 70-100 days of age

3 groups:1. Isolated2. Exposed to co-housed siblings3. Paired with female voles (same age)

Experiment 1: Fos Induction

Isolated animal Mated animal

Radiolabeled V1aR

Medial Amygdala

MDthal

Experiment 2: V1aR Blockade Subjects: sexually

naïve adult male prairie voles

Bilateral infusion of V1aR antagonist into: Lateral ventricle

(control) Ventral pallidum Medial amygdala MDthal

Test for partner preference

Aragona and Wang 2008

Nissl: Bilateral placement of V1aRantagonist in VP

Nissl: Bilateral placement of V1aR antagonist in medial amygdala

Radiolabeled V1aR antagonist confined to VP

Nissl: Bilateral placement of V1aR antagonist in

MDthal

Experiment 3: Increase V1aR in VP Subjects: sexually naïve, adult male prairie

voles Unilateral infusion into VP:

AAV-V1a viral vector AAV-lacZ (control)

Animals recovered for 2 weeks Two groups (2 h):

Exposed to receptive females Isolated

Partner preference and Fos expression analyzed

Mated male prairie vole

Isolated male prairie vole

Autoradiography of V1aR

Difference in Fos cells

Mating-induced Fos Expression Sociosexual and reward structures

activated after mating Medial amygdala Bed nucleus of stria terminalis Medial preoptic area

Regions may be involved in general social behaviors

Fos activation not dependent solely on mating behavior Many steps involved in mating with female

VP and Pair bonding

Vasopressin in medial amygdala and MDthal not heavily involved in pair bonding

VP heavily interconnected with NAcc and mesolimbic dopamine reward pathway

V1aR in VP found in the monogamous: Pine vole Marmoset California mouse

VP and Vasopressinergic Transmission Vasopressinergic neurotransmission in

the ventral pallidum is critical for pair bond formation in the prairie vole

Future work: Vasopressinergic neurotransmission in ventral forebrain of prairie voles?