physiological basis of animal behaviour · mod002787 biological bases of behaviour dr. toby carter...

MOD002787 Biological Bases of Behaviour

Dr. Toby Carter (Bry 114, x 2777) [email protected]

Physiological Basis of Animal Behaviour Physiological Basis of

Animal Behaviour

The Nervous System

Introduction Internal Structure

Figure 44.1

Figure 44.1

Reference: Gray (2002) Chap. 5

The Nervous System I

•  Functions of the Nervous System •  Neurons and Glial cells •  Nerves •  Tracts and Nuclei (CNS) •  The Nerve Impulse •  Synapses •  The Peripheral Nervous System

The Spinal Reflex

Functions of the Nervous System •  Receive Sensory Input •  Manipulate Information

– Organise –  Integrate – Store

•  Stimulate Effectors: Organs or cells that... – Produce Something – Carry out Specific Sets of Instructions – Do Mechanical Work

•  Conscious Experience

A Motor Neuron



Physiological Basis of Animal Behaviour Neuron Structure Glial Cells

Neurons and Glial Cells

•  Parts of Neurons: –  Dendron (-ites) –  Cell Body –  Axon –  Terminals

•  Structure of Neurons: –  Unipolar (Monopolar) –  Bipolar –  Multipolar

•  Types of Neuron: –  Sensory –  Intermediate –  Motor

•  Glial Cells (Glia) –  Myelin Sheaths –  Barriers

Nerves and Tracts •  NERVE:

– a bundle of axons of sensory or motor neurons existing anywhere outside the CNS

•  Types: – Cranial Nerves (12 pairs) – Spinal Nerves (31 pairs)

•  Most nerves are sensory and motor •  SOMATOSENSATION: senses of the body •  Tracts – bundles of nerve fibres in CNS

Somatosensory & Motor Cortex



Physiological Basis of Animal Behaviour The Nerve Impulse

•  Membrane Polarised - Resting Potential –  negative inside (-70 mV)

•  Membrane De-polarised - Action Potential –  positive inside (+40 mV)

•  Membrane Re-polarised - Resting Potential –  after ~2 milliseconds

•  Refractory Period

•  Transmission

•  ‘All or Nothing’

Resting Potential

Potassium Equilibrium Potential Nernst Equation



Physiological Basis of Animal Behaviour Synapses

•  Structure – Synaptic Cleft – Synaptic Vesicles – Pre- and Post-Synaptic Membranes

•  Transmission – Chemical transmitter released into synaptic cleft

•  Features – Unidirectional, Fatigue, Inhibition

Peripheral Nervous System (PNS) •  Voluntary

•  Active Control (Muscular)

•  Autonomic •  No Active Control

– Parasympathetic •  Ganglia •  CNS and Bottom 2 Spinal Nerves

– Sympathetic •  Direct Action •  Spinal Nerves

Divisions of PNS Major Portion of

Peripheral Nervous System

Skeletal Autonomic

Sympathetic Parasympathetic

•  ^ Heart Rate & Pressure •  Release of Energy •  ^ Blood to Muscles •  Inhibit Digestion

•  Relaxed •  Regenerative

Divisions of PNS

The Nervous System



Physiological Basis of Animal Behaviour CNS I: The Spinal Cord

•  Three Important Functions – carries messages up & down – generates rhythmic component of movement –  (Pattern Generators) – spinal reflexes

•  Tracts

CNS II: Hindbrain and Midbrain •  Brainstem (medulla, pons, midbrain) & Thalamus

– Medulla and Pons: complex reflexes – Midbrain & Pons: sleep and arousal – Thalamus: relay station

Brainstem and Thalamus CNS II: Hindbrain and Midbrain •  Brainstem (medulla, pons, midbrain) & Thalamus

– Medulla and Pons: complex reflexes – Midbrain & Pons: sleep and arousal – Thalamus: relay station

•  Cerebellum & Basal Ganglia – Cerebellum: initiation & co-ordination of rapid

movement – Basal Ganglia: Slower deliberate movement

Cerebellum and Basal Ganglia CNS III: The Limbic System incl. Amygdala & Hippocampus

– Limbic system • basic drives & emotions

– Hippocampus • memory formation

– Hypothalamus: •  regulation of internal environment • and emotional states



Physiological Basis of Animal Behaviour Limbic System and

Hypothalamus Fornix

CNS IV: The Cerebral Cortex •  Lobes:

– FRONTAL – PARIETAL – TEMPORAL – OCCIPITAL

•  Areas: – PRIMARY

SENSORY – PRIMARY MOTOR – ASSOCIATION

•  Association Areas: – Perception – Thought – Decision Making

THE FOUR LOBES

Observe the relative size differences of certain regions in the different taxa

Asymmetry of Cerebral Cortex

•  Distinct hemispheres connected by corpus callosum

•  Symmetrical in basic sensory & motor functions

•  Asymmetrical in Association areas •  LEFT: Language •  RIGHT: Spatial Relationships

Lateralisation



Physiological Basis of Animal Behaviour Gouldian finches

-  Morphs prefer to mate with their own colour - Tested mate choice using only right eye, only left eye or both

- Very strongly lateralised – use right eye/left hemisphere in mate choice

Templeton et al. (in press) doi: 10.1098/rsbl.2012.0830

Summary •  Neurons and how they work •  PNS

– nerves – voluntary & autonomic – sympathetic & parasympathetic

•  CNS – Tracts – Spinal Cord & Brain

•  Functions of Different areas of the brain •  The Cerebral Cortex

CNS II: The Brain 2 •  Limbic System (incl. Amygdala & Hippocampus)

– Limbic system: basic drives & emotions – Hippocampus: memory formation – Hypothalamus: regulation of internal

environment & emotional states •  Cerebral Cortex

– Lobes: FRONTAL, PARIETAL, TEMPORAL, OCCIPITAL

– Areas: PRIMARY SENSORY, PRIMARY MOTOR, ASSOCIATION

– Association Areas: Perception, Thought, Decision Making

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