Neurobiology and Behaviour (Option C)

Neurobiology and Behaviour Overview

This topic explores the complex relationship between the nervous system and behaviour.
Neurobiology is a branch of biology that focuses on the study of the nervous system, while behaviour refers to the observable activities of an organism in response to external or internal stimuli.
It encompasses how the sensory organs perceive environmental stimuli, how the nervous system processes this information, and how it ultimately leads to behavioural responses.

The nervous system is a complex network of neurons and glial cells that transmit and process information.
The nervous system is broadly divided into two sections: the central nervous system (CNS) which includes the brain and spinal cord, and the peripheral nervous system (PNS), which includes the nerves outside of the CNS.
Neurons are specialised cells that transmit electrical and chemical signals in the body. They have a cell body (soma), axons (for outgoing signals) and dendrites (for incoming signals).
Glial cells or neuroglia are the support cells of the nervous system. They aid in neuron function, provide physical support, maintain nutrient supply, and participate in the immune response.

Sensory reception refers to how organisms receive and interpret external and internal signals through sensory receptors.
Sensory receptors transduce physical and chemical stimuli into nerve impulses that can be interpreted by the nervous system.
There are five main types of sensory receptors: chemoreceptors (for chemicals), photoreceptors (for light), mechanoreceptors (for force or pressure), thermoreceptors (for temperature), and nociceptors (for pain).

Once a sensory receptor receives a stimulus, this information must be processed by the nervous system.
Information travels as an electrical signal, or action potential, along a neuron. This action potential is generated by the movement of ions across the neuron membrane.
At the synapse, the electrical signal triggers the release of neurotransmitters, which carry the signal to the next neuron by crossing the synaptic cleft.
The brain integrates all the sensory information from various sources and coordinates the response.

Behaviour is a response to environmental or internal stimuli. Behaviour includes simple responses such as reflexes, as well as complex behaviours like learning, memory, and social interaction.
Actions such as running away from a perceived threat, or feeding when there is food available, are survival behaviours governed by the nervous system.
These behaviours can be instinctive, learned through experience, or a combination of both.
Instincts are innate behaviours that are performed correctly the first time they are triggered. They’re generally the result of evolution and are encoded in the genes.
Learned behaviours are acquired or modified by experience. Learning can involve habituation, classical conditioning, operant conditioning, or cognitive learning.