Class Notes (839,094)
Canada (511,185)
Neuroscience (303)
NROC34H3 (27)
Lecture

NROC34 Lec 6.docx

10 Pages
173 Views

Department
Neuroscience
Course Code
NROC34H3
Professor
Karen Williams

This preview shows pages 1,2 and half of page 3. Sign up to view the full 10 pages of the document.
Description
NROC34 Lec 6 Last lec: birds - Zebra finch pairs - Giving oxytocin antagonist, might change what is happening - Zebra Finch pair preening picture o Have pair bonded and have pair bonding behaviour o Sensory cues are what we look at o With bird songs – can see that birds pair o Males sing, females do not - Infusion of antagonist of oxytocin o Has NO effect on male song o Reduces pair bonding behaviours of females o Happens in other organisms also - In humans, oxytocin is for maternal behaviour, etc - Voles and vasopressin - Mostly based on readings in text - In prairie voles – known to huddle together o The pair are sitting together with the babies under o Female voles rarely re-mate o Males aggressively defend territory and protect the female - Sensory cues that might be important for behaviour depicted in the picture: o Olfaction – can smell mate o Tactile/touch cues – are huddling - Are there any compounds we might know are important for pair touch behaviour The scientific method - Very important for review – look at article and look at these areas o Hypothesis, predictions o Methods o Results o Discussion - For scientific method, have an idea from other organisms (sheep and lambs) that oxytocin might be important for lambs and sheep for when the sheep have just given birth - In pair bonding, something about touch, etc. are important Vole behaviour: monogamy - Prairie voles are monogamous - Montane and others are polygynous - When mammals exhibit close bonds  correlated with elevated brain levels of OXYTOCIN and VASOPRESSIN Social behaviour of voles - Look at all aspects of behaviour that we can describe - Chart o Look at prairie voles vs. montane voles - All these behaviours for monogamous prairie voles, can ask if they are the same for the montane voles o Many are different - Prairie voles are biparental, while montane are maternal What affects bonding behaviours in other animals? - What makes bonding behaviours? o Sheep and lambs – mothers bond with offspring - Do oxytocin and vasopressin change among the voles with the different mating systems? - In other animals – mammals, mice – can use to get a hypothesis Vasopressin and oxytocin: neuroanatomy - More vasopressin binding in the ventral pallidum of the prairie voles than montane voles - Oxytocin R bind in the Nacc in prairie voles but not so much in montane voles - Just looking at neuroanatomy, can already see differences in behaviour - Look at contact time: o Those cohabiting together  Contact time increases than with a stranger  Most when arginine vasopressin or oxytocin o Mated condition  Mating is higher with partner than with stranger in control (CSF)  When given antagonist for vasopressin R – the difference disappears  stay beside partner and stranger same amount of time  When giving antagonist for oxytocin R – it completely reverses  Contact time with a stranger is much higher - From the different levels in anatomy, can ask physiologically what will happen if we pharmacologically change levels - Partner preference behaviour o Differs in prairie voles and montane voles - Can plot the relationship - Most voles are polygamous, some have variable, few are monogamous - Looking at prairie vole vs montane partner preference Scientific Method - Hypothesis: o Do voles with different mating systems show differences in these hormones? - Prediction: if vasopressin is involved in the pair-bonding behaviour of voles, then changing the level of vasopressin would change the behaviour o Start with ones that are promiscuous and see if we can change pair-bonding behaviour - Methods: Does vasopressin receptor gene influence pair bonding behaviour? - Measure time in contact of stranger, partner - Control: lac-Z - Methods: o Measure time in contact  Of lac-Z vs V1aR in ventral pallidum (VP) or caudate putamen (CP) - V1ar in caudate putamen – contact with a stranger is higher - V1ar put in ventral pallidum – contact with partner is much higher – significantly higher o Large difference - Can conclude: o Talk about VP and CP results Partner Preference Test - Recorded the behaviour of the voles and measured time vole spent in contact with the partner - How close does animal have to be with partner for contact Does this genetic factor change the proportion of animals displaying the behaviour? - Can also ask about voles with different mating systems - Could we change a polygamous vole into a monogamous vole by increasing vasopressin receptor? o Is the difference between partner preference behaviour between monogamous Prairie voles and promiscuous Montane voles affected by v1ar?  Can genetic factor change proportion of animals? - Results: time spent huddling in the prairie voles is higher and in montane – is the same as time spent near stranger o NEED TO KNOW BASIS FIRST - Hypothesis: monogamy (time spent huddling) is not different between genetically modified v1ar bearing male voles and control unaltered male voles - Results: o Expression of v1ar in VP increased pair bond formation for ordinarily promiscuous voles o Know VP is the only place that changes this behaviour - Possible that the time spent huddling is much greater when they are genetically modified with vasopressin R - Conclusion: o Gives us an idea of another question to ask o Monogamous behaviour can be described in a variety of ways o Biparental care could be increased o Vasopressin R = v1ar or avpr1a Biparental care - Hypothesis: overexpression of avpr1a in VP increases the parental care behaviour in prairie voles - Methods: parental care behaviours o Latency to retrieve pups  Different times in prairie vs montane - Results: o In prairie voles, found NO significant difference in parental care – different from other results o Would normally expect major differences when we express in montane voles o Increasing avpr1a in montane voles – don’t increase parental care either - Conclusion: mechanisms by which expression of v1ar influences pair-bond formation is different from those that affect biparental care o Increased avpr1a in VP does NOT increase the parental care behaviour o Both, though, are behaviours to describe monogamy Neuropeptide R plasticity associated with pair-bonding experience - V1ar in sexually naïve voles vs. voles that mated from pair bonding o The ones that pair bonded had more vasopressin expressed in certain areas o Anterior hypothalamus – naïve have less expression than pair bonded - Behaviour changes expression of behaviour - There is some plasticity in specific parts of the brain but not all Selective Aggression - The aggression naïve male voles direct to unfamiliar females is increased by adding vasopressin R to the anterior hypothalamus (AH) but NOT to the lateral septum o More aggressive towards random females when adding vasopressin R to AH - VP important for partner preference. No difference for parental care - Looked at anterior hypothalamus and lateral septum. Note: they are areas that would change with pair bonding - Measured aggression of naïve voles to novel females when expressing vasopressin R in the AH vs. expressing lac-Z - Results: o Typical low aggression with lac-Z – vasopressin caused high aggression  Increased aggression by adding v1ar in AH o Affiliation  Control = higher o V1ar binding  When giving vasopressin – much higher in AH than control  In lateral septum – v1ar binding is the same as control group - Aggression was higher in monogamous roles 1.6 - Proximate and internal mechanisms - Arginine vasopressin gene – important to specific areas of the brain What physiological mechanisms are involved? - Because of pair-bonding behaviour changing expression, expect reward circuit will be involved - Physiological methods that might be involved: o Olfaction  Could give some reward - Dopaminergic signalling o Give DA R antagonist – haloperidol o DA R agonist – apomorphine o (see pg.43) - Hypothesis about reward circuit: - Prediction: if you were to give antagonist vs agonist - Methods: measure huddling in voles using contact times. Measured this by using partner preference test - Results: o Describe EVERY part of the graph - Conclude: - If we were going to repeat experiment again, what dosage of apo would be used? What further experiments would be done? o Tried different doses to see the range of behaviours o With organisms – not sure which dosage to give. Want to check dose response o Might have to do other experiments if going to use high dose of apo. See if it has different effects – makes animal sick, etc How does dopamine affect behaviour? - Mating induces a change o Contact time is much higher with CSF - If mating gives a reward, can block that reward change by giving the D2 antagonist o Does it block that reward and reduce contact time? o We can block pathway and
More Less
Unlock Document

Only pages 1,2 and half of page 3 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit