Neurobiology

1. What is neurobiology? Neurobiology is the study of the nervous system, which includes your brain, spinal cord, and all the nerves in your body. It aims to understand how this system controls what we do, feel, think, and how we move. It also looks at how our body processes information.

2. The nervous system: Think of your nervous system as your body’s communication network. It detects changes around and inside you, processes this information, and coordinates how you respond. It’s made up of two main types of cells:
   • Neurons: These are like the messengers, sending electrical signals throughout your body.
   • Glial cells: These are the support team, helping neurons do their job by providing structure, food, and protection.
3. Neurons: A neuron is like a tiny biological wire. It has three main parts:
   • Cell body: This is the control center, containing the nucleus which directs the cell’s activities.
   • Dendrites: These are like antennae, receiving signals from other neurons.
   • Axon: This is like a long cable that sends signals to other neurons or muscles.

   Neurons communicate by creating electrical impulses called action potentials. These impulses travel down the axon and then get converted into chemical signals to pass the message to the next cell.

4. Action potentials: An action potential is like a wave of electricity that moves along a neuron’s axon. It’s created by the movement of charged particles (ions) in and out of the neuron. Here’s how it works:
   • Normally, the inside of a neuron is negatively charged compared to the outside.
   • When stimulated, positive ions rush in, making the inside more positive.
   • This creates a wave of electrical charge that moves down the axon.
   • Afterward, different ions move out to reset the neuron to its normal state.

   This process allows neurons to send messages quickly over long distances in your body.

5. Synapses: A synapse is like a tiny gap between neurons where they pass messages to each other. Most communication at synapses is chemical. When an electrical signal reaches the end of an axon, it triggers the release of chemicals called neurotransmitters. These chemicals cross the gap and attach to the next neuron, either exciting it or calming it down.

6. Neurotransmitters: Neurotransmitters are chemical messengers that carry signals across synapses. They’re crucial for regulating things like mood, memory, and body functions. Different neurotransmitters have different jobs:
   • Dopamine is involved in feeling rewarded and motivated.
   • Serotonin affects mood, sleep, and appetite.
   • Acetylcholine helps with muscle control and memory.
   • GABA helps calm the nervous system.
7. The brain: The brain is like the command center of your nervous system. It processes information, makes decisions, and sends out commands. It’s divided into different areas that specialize in different tasks:
   • The cortex handles complex thinking and decision-making.
   • The cerebellum coordinates movement and balance.
   • The brainstem controls automatic functions like breathing.

   The brain is made up of billions of connected neurons forming complex networks. It can change and adapt by forming new connections, which is called neuroplasticity.

8. Nervous system organization: The nervous system is divided into two main parts:
   • Central nervous system (CNS): This includes your brain and spinal cord. It’s like the main processing unit.
   • Peripheral nervous system (PNS): This includes all the nerves outside the CNS. It’s like the network of wires connecting the CNS to the rest of your body.

   The PNS is further divided into:

   • Somatic nervous system: Controls voluntary movements, like moving your arm.
   • Autonomic nervous system: Regulates involuntary functions, like heart rate. It has two parts:
   • Sympathetic: Activates your “fight or flight” response.
   • Parasympathetic: Promotes “rest and digest” functions.
9. How neurobiology works: Neurobiology, like other sciences, follows the scientific method:
   1. Scientists observe behaviors or changes in the nervous system.
   2. They form ideas (hypotheses) about how things might work.
   3. They test these ideas through experiments.
   4. They develop theories to explain how the nervous system functions.
   5. This knowledge is applied to understand diseases or create new treatments.
10. Fundamental principles in neurobiology: Some key principles in neurobiology include:
    • Electrochemical gradients: Neurons use differences in ion concentrations to generate electrical signals.
    • Synaptic plasticity: Connections between neurons can get stronger or weaker, which is how we learn and form memories.
    • Homeostasis: The nervous system helps maintain stability in the body by regulating things like temperature and blood pressure.

In summary, neurobiology looks at how your brain, spinal cord, and nerves work together to control everything your body does.