How Do Neurons Work?
Neurons, the fundamental units of the brain and nervous system, communicate through a combination of electrical and chemical signals. This intricate process allows for the transmission of information throughout the body, enabling everything from basic reflexes to complex thought.
Neurons are "excitable" cells, meaning they generate electrical events called action potentials (also known as nerve impulses or spikes). These action potentials are rapid changes in the neuron's electrical potential, acting like an "on" or "off" switch. The flow of positively charged ions across the neuronal membrane drives this process. [^1][^10]
The Chemical Signal: Neurotransmitters
Communication between neurons occurs at specialized junctions called synapses. When an action potential reaches the end of a neuron's axon, it triggers the release of neurotransmitters, chemical messengers, into the synapse. These neurotransmitters then diffuse across the synapse and bind to receptors on the dendrites of the neighboring neuron. This binding can either excite or inhibit the receiving neuron, influencing the likelihood of it firing its own action potential. [^1]
Types of Neurons
Neurons aren't all the same; they come in different types, each with a specific role:
- Sensory neurons: Transmit information from sensory organs (like eyes and ears) to the brain. [^1]
- Motor neurons: Carry messages from the central nervous system (brain and spinal cord) to muscles and glands, directing movement and other bodily functions. [^4]
- Interneurons: Connect sensory and motor neurons, relaying information within the central nervous system. [^3]
How Neurons Work Together
Individual neurons rarely act alone. They work together in complex networks, with the activity of one neuron influencing the activity of many others. This interconnectedness allows for the processing of vast amounts of information and the execution of sophisticated functions. [^5] The brain’s ability to identify phenomena, weigh options, and reach conclusions depends on neurons working collaboratively. [^9] For instance, in the auditory cortex, single-neuron recordings have helped illuminate how acoustic stimuli are represented and processed through this collective neuronal effort. [^5]
The Impact of Drugs and Disease
Drugs can significantly affect neuronal function by influencing neurotransmitter release, receptor binding, or reuptake (the process by which neurotransmitters are removed from the synapse). [^6] Diseases like Alzheimer's can lead to neuronal dysfunction and death, disrupting communication and impacting cognitive abilities. [^7]
Sparse Distributed Representations
Some models propose that neurons operate on sparse distributed representations, where information is encoded across a relatively small subset of neurons within a larger network. This efficient coding scheme is believed to be important for the brain's ability to handle complex information. [^8]
[^1]: Neurons communicate with each other by sending chemicals, called neurotransmitters, across a tiny space called a synapse, between the axons and dendrites of nearby neurons. There are three kinds of neurons: Sensory neurons carry information from the sense organs (such as the eyes and ears) to the brain.
[^3]: Depending on its location, a neuron can perform the job of a sensory neuron, a motor neuron, or an interneuron. Each of these types of neurons…
[^4]: Connection. Efferent neurons — these take messages from the central nervous system (brain and spinal cord) and deliver them to cells in other parts of the body.
[^5]: Recordings of single neurons have yielded great insights into the way acoustic stimuli are represented in auditory cortex. However, any one neuron functions…
[^6]: …neuron that released them), thereby limiting or shutting off the signal between neurons. How do drugs work in the brain?
[^7]: …neurons stop working properly and eventually die. Key biological processes in the brain.
[^8]: We propose a formal mathematical model for sparse representations and active dendrites in neocortex.
[^9]: ...neurons work together to identify phenomena, weigh options and arrive at conclusions.
[^10]: Neurons conduct electrical impulses by using the Action Potential. This phenomenon is generated through the flow of positively charged ions across the neuronal…
