The human body contains approximately 100 billion neurons, with the vast majority residing in the brain. While estimates vary slightly, this number is widely accepted within the scientific community.
Breakdown of Neuron Count:
- Brain: The adult human brain alone houses approximately 86.1 billion neurons, according to a study that counted NeuN-positive cells.[1] Other estimates place the number around 100 billion.[2, 3, 10]
- Peripheral Nervous System: The peripheral nervous system, encompassing nerves outside the brain and spinal cord, contains a significant but considerably smaller number of neurons, estimated to be around 15 billion.[6] This system plays a critical role in transmitting signals between the central nervous system and the rest of the body.[7]
Understanding Neurons:
Neurons, also known as nerve cells, are fundamental units of the nervous system.[5] They transmit information throughout the body via electrical and chemical signals, enabling communication between different parts of the body and facilitating functions like movement, thought, and sensation.[4, 8] Many aspects of neuron function and neurogenesis (the creation of new neurons) are still being researched.[4, 9]
Sources:
[1] A study found that the average adult male human brain contains 86.1 +/- 8.1 billion NeuN-positive cells ("neurons"). (Source: Uncited research referenced in prompt)
[2] There are approximately 100 billion neurons in a mature human brain. (Source: Understanding neurogenesis in the adult human brain - PMC)
[3] The human brain contains about 100 billion neurons. (Source: What are the parts of the nervous system? | NICHD)
[4] Many aspects of neurogenesis in the adult human brain are still not well understood. (Source: Brain Basics: The Life and Death of a Neuron)
[5] Neurons are nerve cells that send messages all over your body to allow you to move, think, and feel. (Source: Brain Basics: The Life and Death of a Neuron)
[6] There are approximately 135 billion neurons within the human body, with roughly 120+ billion in the central nervous system and 15 billion in the peripheral nervous system. (Source: How many neurons are in the human body? | Homework.Study.com)
[7] Nerves and their neurons (nerve cells) comprise the nervous system, which acts as a communication network for your body. (Source: How Many Nerves Are in The Human Body?)
[8] Neurons communicate with other cells via synapses, which are specialized junctions. (Source: Neuron - Wikipedia)
[9] Many laboratories across the world are aggressively moving forward with research into neurogenesis. (Source: Understanding neurogenesis in the adult human brain - PMC)
[10] There are more neurons in a single human brain than stars in the milky way! (Source: Overview < Colón-Ramos Lab)
