Lecture 1: Matheson Flashcards
Define behaviour
all observable processes by which an animal responds to perceived changes in the internal state of its body or in the external world
What are Tinbergen’s four questions
How is this behaviour achieved
How does the behaviour develop?
What is the behaviour for?
Where has the behaviour come from?
Which of Tinbergen’s four questions are proximate?
How is this behaviour achieved?
- Mechanism
How does the behaviour develop
-Development / plasticity
Which of Tinbergen’s four questions are ultimate?
What is the behaviour for?
-Function
Where has the behaviour evolved from?
-Evolution
Define Neurons:
Electrically excitable cells that have one or more neurites from their soma
Define Neurites
Protrusions / extensions from the cell body
- Axons –> output
- Dendrites –> input
How do neurons communicate with one another
Electrical or chemical synapses
Via neuromodulators / neurohormones
Define a Sensory Neuron
A nerve cell that receives information from the internal or external environment and transmits signals to the central nervous system
Define a Motor Neuron:
A nerve cell that transmits information from the brain / spinal cord to an effector
Define an Inter-neuron:
A neuron that transmits impulses between other neurons, especially as part of a reflex arc
Define: an Exteroceptor
A sensory receptor that receives external stimuli
Define: a Proprioceptor
A sensory receptor that receives internal stimuli
Define: Cortical Neuron
the neurons which make up the cerebral cortex
Define: Local interneuron
Forms a connection between other neurons
Define: ipsilateral
A nerve which runs down the same side of the body the whole time
Define: contralateral
A nerve which runs down the body and changes sides from its origin
Define: Membrane Potential:
Voltage difference across a membrane
Define: Equilibrium Potential:
The voltage at which there is no net movement of the ion species, in a single ion species system
Define: Reversal Potential:
The potential at which there is no net movement of the ion species. Calculated with the Nernst Equation.
Define: Voltage gated ion channel
An ion channel which opens at a specific membrane potential
Define: Ligand gated ion channel
An ion channel which ones when a signalling molecule binds to it
Define: Spike Threshold
The membrane potential at which voltage gated sodium channels begin to open which leads to an action potential
Define: Generator Potential
Graded potential in sensory neurons, caused by a stimulus, which will produce an action potential if it reaches the spike threshold
What is the function of neurons
Receive, gather and transmit electrical and chemical signals
What causes the resting membrane potential to be set where it is (-65mV)
Permeable to K+ ions so close to Ek.
Large negative proteins on inside of membrane which can’t pass through –> large electrical gradient to flow into the cell.
How are signals passed along a nerve cell
Action potentials
- brief depolarization which doesn’t decrease in size and is formed in an all or nothing event
Graded response:
- passive propagation
How are Post synaptic potentials formed (PSPs)
Depolarisatin –> calcium influx through voltage gated channels –> vesicles released neurotransmitter into synaptic cleft –> hyperpolarisating or depolarising effect –> Post synaptic potential depending on the receptors affected
EPSP is positive compared to spike threshold
IPSP is negative compared to spike threshold
What are the properties of post synaptic potentials
Able to summate without a decrease and build up to a larger signal in turn
Able to facilitate (summate with decrease in between)
Able to depress (increased frequency of signals leads to decreased amplitude
What signalling molecules are released at synapses
Neurotransmitter: direct effect of post-synaptic cell
Neuromodulator: released in vicinity of post-synaptic cell
Neuro-hormone: released into blood stream for distant action
What is the purpose of electrical synapses
Rapid information transfer between cells
Found in locations where speed is important
