Brain and Behaviour Flashcards
What is the hypothalamus?
The region in the ventral (lower) brain which co-ordinates the endocrine system
What is the endocrine system?
A control system of ductless glands that secrete hormones
What is the pituitary gland?
An endocrine gland in the brain that is attached to the hypothalamus of the lower forebrain
What is the hypothalamic-pituitary axis?
A complex set of interactions between the hypothalamus, pituitary gland, and other endocrine glands in the body
It plays a crucial role in regulating various physiological processes, including stress responses, growth, metabolism, and reproductive functions
What is oestrogen?
A hormone in females that stimulates the development of the uterus and vagina
What is the pineal gland?
A small endocrine gland in the brain located near the centre of the brain, between the two hemispheres, tucked into a groove where the two rounded thalamic bodies join
What are steroids?
Hormones that are lipids synthesised from cholesterol characterised by four interlocking carbohydrate rings
What is testosterone?
A hormone more prominent in males, belonging to the androgen family (steroid hormones producing masculinising effects)
What is the thyroid gland?
An endocrine gland that consists of two lateral masses attached to the trachea
What is thyroxine?
A hormone that serves to stimulate oxidative metabolism in cells, increasing the oxygen consumption and heat production of most body tissues
What is neuroendocrinology?
The study of how the brain and hormones interact in behaviour
What is a hormone?
A signalling molecule that exerts its effects far from its site of production
What are the classes of hormones?
Steroidal:
- Adrenal
- Sex (male and female)
Non-steroidal:
- Peptides
- Amino acid derived
- Miscellaneous
What are trophic hormones?
Hormones that stimulate growth and development of endocrine glands
Typically secreted by anterior pituitary
What are endocrine cells?
Cells which release their hormones into the second set of capillaries for distribution to the rest of the body
What are the two most important principles of endocrinology?
1) Feedback: e.g. the hypothalamus releases a hormone that stimulates the pituitary to release tropic (regulatory) hormones in feedback (typically negative) to regulate the activity of the hypothalamus and pituitary, maintaining hormonal balance
2) Pulsatility: Refers to the rhythmic, episodic secretion of hormones in pulses rather than a continuous stream - crucial for maintaining proper hormone regulation and ensuring the effectiveness of signalling
Describe how oestradiol secretion is regulated.
Low concentrations of oestradiol inhibit LH and FSH output
High concentrations of oestradiol stimulate LH and FSH output
What is the paraventricular nucleus (PVN)?
A region in the hypothalamus that regulates hormone release by producing oxytocin, vasopressin (ADH), and corticotropin-releasing hormone (CRH), influencing stress response
Also helps control autonomic functions like appetite, blood pressure, and fluid balance
Located near the third ventricle
What is the supraoptic nucleus (SON)?
A cluster of neurones in the hypothalamus that primarily produce vasopressin (ADH) and oxytocin, which are then transported to and released from the posterior pituitary gland
Positioned above the optic nerve
Main role is fluid balance and osmoregluation
What are the two main divisions of the nervous system?
Central Nervous System
Peripheral Nervous System
What are the three main components of the central nervous system?
Spinal cord
Brain stem
Brain
What are the two divisions of the peripheral nervous system?
Somatic (controls voluntary movements)
Autonomic (regulates involuntary process, i.e. heart rate)
What are the two divisions of the autonomic nervous system?
Sympathetic: prepares body for stress (fight or flight)
Parasympathetic: calms the body and helps to conserve energy
What is oxytocin?
A hormone and neurotransmitter produced in the hypothalamus and secreted by the pituitary gland
What are the roles of oxytocin?
To promote uterine contractions
To stimulate milk ejection during breastfeeding
To promote maternal bonding
To promote placental prostaglandin secretion
Describe how oxytocin secretion occurs during lactation.
Babies suckling stimulates sensory receptors in the nipple
This activates spinal nerves, projecting to the hypothalamus to cause oxytocin secretion
Oxytocin is carried down to the mammary gland, where it acts on myoepithelial cells, causing milk to be let down
Pulsatility of oxytocin is short lasting - each burst doesn’t last long
How does the behaviour of a nulliparous rat differ to a multiparous rat when interacting with pups?
Nulliparous rats (have never experienced birth or lactation) do not show interest in interacting with pups or caring for them
Multiparous rats (have experienced pregnancy, birth, and lactation) show distinctive maternal behaviour, e.g. nest-building
Describe the results of the partner-preference test on prairie voles.
Prairie voles are monogamous - spending most of their time with their partner compared to in the neutral and stranger chamber
Describe the results of the partner-reference test on montane voles.
Montane voles are non-monagmous - they spend most of their time by themselves in the neutral chamber and roughly equal amounts in the partner and stranger chambers
How does an OXTR antagonist impact partner-reference formation with prairie voles?
OXTR antagonists are oxytocin receptor blockades, so prevent partner-preference formation in a mating pair of prairie voles
They therefore spend less time in immobile social contact (cuddling) and equal time with partner and stranger, showing no preference
What is the effect of alcohol consumption on partner-preference formation in prairie voles?
For female prairie voles: they tended to spend more time with their partner and less with strangers
For male prairie voles: they tended to spend less time with their partner and roughly a similar amount of time with a stranger (no preference)
How do rats express positive and negative emotions?
via ultrasonic vocalisations (USVs):
22kHz: typically negative, e.g. aggressive behaviour and drug withdrawal
50kHz: typically positive, e.g. sexual behaviours, intra and inter-species play
What is the Mesolimbic reward pathway?
A neural circuit in the brain associated with motivation, pleasure, and reinforcement learning
It plays a crucial role in processing rewards and is heavily involved in addiction and mood regulation
What are some potential reasons for play for animals?
Training for ‘serious work’
To discharge surplus physical energy
Expression of a motivation to perform certain physical actions
A safe way of expressing harmful impulses
A way to develop social restraint
A form of imitation of conspecifics (other animals)
