Lecture 5

Question 1

What does behaviour involve?

Answer 1

Behaviour involves a coordinated muscular response

Sensory system > Nervous system > Behaviour

Question 2

Peripheral nervous system vs Central nervous system

Answer 2

Simple reflexes- PNS (peripheral) nerves ganglia outside of brain/spinal cord (connects CNS to limbs/organs)

Complex behaviours- CNS (central)
◼ Much more protected (spinal column/skull) so less damage

Often modulated by hormones
◼ Facilitate or inhibit a specific behaviour

Question 3

What is an example of the Interaction of Physiology and Behaviour

Answer 3

High testosterone leads to increased aggression BUT Losing a fight decreases testosterone production

Question 4

What are the differences between the Neural and sensory system and the hormonal and pheromonal system?

Answer 4

Neural and sensory systems
❑ electrical
❑ fast acting
❑ central (CNS) and peripheral (PNS)

Hormonal and pheromonal systems
❑ chemical
❑ longer acting ex. seasonal
❑ target specific tissues

The two systems are interconnected: Neural—> hormonal via hypothalamus
Pheromonal —> neural via sensory systems

Question 5

Where is the hypothalamus?

Answer 5

in the Brain region adjacent to pituitary gland

Question 6

What is the primary function of the
hypothalamus?

Answer 6

❑ Controls master gland (pituitary)- importance of these 2 organs
❑ 2 H’s homeostasis and hormones
◼ Senses what is wrong
❑ Produce releasing and inhibitory hormones

Brain region adjacent to pituitary gland

Secretes ‘releasing hormones’
◼ Ex. GHRH (growth hormone releasing hormone), CRH (corticotropin releasing hormone), GnRH (gonadotropin releasing hormone)
Causes release of pituitary hormones into
circulation -> act on target tissues

Question 7

What are simple reflexes?

Answer 7

patellar, blink, swallow

Question 8

What are Complex behaviours?

Answer 8

courtship, nesting, feeding

Question 9

What are the properties of neural response?

Answer 9

Properties of neural response:
1. Initiation
2. Coordination
❑ Response Inhibition
3. Control
❑ Latency, refractory period,
homeostasis

Question 10

What is initiation in the properties of neural response?

Answer 10

Stimulus internal or external

Threshold and Action Potential (Response) - Moving ions (sodium or potassium) depolarizes membrane potential, nerve gets excited and get a response

Summation – temporal or spatial- whether or not enough to cause action

Electrical activity of neurons
❑ Moving of ions to reach state where
membrane potential is depolarized to
initiate action potential
◼ Response to stimulus- neural
response must exceed threshold
to initiate an action potential
❑ ‘All or nothing’ response

Question 11

What year was Neurophysiology discovered?

Answer 11

1906 by Sherrington

Question 12

What is Summation?

Answer 12

Multiple inputs combine to initiate a response

Question 13

What is Temporal summation?

Answer 13

Stimulus is repeated over time single neuron rapid-firing

Question 14

What is Spatial summation?

Answer 14

Repeated at multiple site multiple neurons sending signals

Question 15

What is inhibition and coordination in the properties of neural response?

Answer 15

Inhibition is necessary for coordination
◼ Neural inhibition
❑ Walking: opposing muscles are
inhibited
◼ Behavioural inhibition
❑ Can only do one thing at a time!
❑ Alternate bouts of feeding and
drinking

Question 16

What is control in the properties of neural response?

Answer 16

Physiology and behaviour balance each other to maintain homeostasis
◼ Energy balance
❑ Input and output
❑ Growth and maintenance

Question 17

What are models for homeostasis and what are examples?

Answer 17

◼ ‘Closed loop’ systems
◼ Feedback mechanisms- performing the behaviour results in inhibition (-)

Thermoregulation
◼ Cold: leads to huddling, shivering
◼ Heat: panting, wallowing, shade
seeking, drinking
Energy balance & hydration
◼ Hunger: hunting, foraging
◼ Thirst: Seek water, drink

2 important organs! - Hypothalamus and Pituitary

Question 18

Do Hormones cause behaviour?

Answer 18

No, They initiate physiological actions which may be necessary for a behaviour

Release could cause another hormone to be released OR Release could directly cause an organ to change behaviour

Question 19

Do hormones have dual action?

Answer 19

Yes, many hormones have dual action:
❑ Act as a neurotransmitter in nervous
system
❑ Act as hormones in circulatory system

Question 20

What are pheromones?

Answer 20

Chemical that is released into the
environment which causes a specific behavioural or physiological reaction in member of same species

Pheromonal system affects hormones via sensory systems
❑ Two main roles-
◼ Signaling (eg estrous- female present)
◼ Priming (eg initiate ovulation cycle

Question 21

What are examples of pheromones?

Answer 21

◼ Naked mole rat
❑ Pheromone suppresses
other females, turning off their cycle
so the male will only mate with her

◼ Synchronization of ovulation cycles (humans)

◼ Ram effect in sheep (initiates cycling by
introducing a ram)

Question 22

What are the 5 main senses? are there any more?

Answer 22

Sight, hearing, touch, smell, taste

Yes depends on the animal

Question 23

What is Umwelt?

Answer 23

German word meaning environment or surroundings, used to describe- “The individual sensory environment and behavioural capabilities of a species”

Animal perceptions vary greatly from human abilities - failure to understand this limits our understanding of animal behaviour

We cannot assume that animals perceive their environment as we do!

Question 24

What is vison?

Answer 24

Vision- is a balance between light sensitivity and colour detection

Significant species differences
❑ Cones – bright light – color vision
❑ Rods – dim light – not responsive to
color

Balance depends on species behaviour and dependence on visual information

Nocturnal species
❑ one receptor type: see grey scale at
high resolution

Crepuscular species
❑ twilight
◼ 2 colours: blue-violet and green

Diurnal species
❑ Humans, birds: see full colour

Question 25

What is the hearing range of humans, cats, dogs, elephants, and bats?

Answer 25

Humans 20 – 20,000
Cats 100 – 32,000
Dogs 40 – 46,000
Elephants 16 – 12,000
Bats 1000 – 150,000

Elephants: Low end- infrasonic
Bats: High end- ultrasonic

Question 26

Elephant hearing

Answer 26

Elephants use infrasonic calls for
communication over long distances
❑ “Contact calls”- used to communicate
location
◼ 21 Hz calls; 4-5 sec in duration
◼ Sounds can travel multiple kilometers

Question 27

What is Electroreception in fish?

Answer 27

using electrical current for Dark environments, Stunning prey, location, communication

Fish/amphibious since salt water is a good
conductor

Question 28

What is Magnetoreception?

Answer 28

❑ Sense magnetic fields, Orientation using earth’s magnetic fields

How does it work?
❑ Possibly via magnetite crystals, or
vision?
❑ Chryptochrome in birds eyes?

What is it?
❑ Found in some bacteria, bees and migratory birds… and cows?
◼ Grazing cows orient predominantly
north-south (2008 study) We don’t
know where the receptors are