Neuroscience is an interdisciplinary field studying the structure and function of the nervous system, integrating biology, psychology, physics, computer science, and medicine. Over the past 30 years, breakthroughs in fMRI, optogenetics, and single-cell sequencing have produced qualitative leaps in human understanding of the brain. In 2013, the US launched the BRAIN Initiative; the EU launched the Human Brain Project the same year; China included “Brain Science and Brain-Inspired Research” in its 14th Five-Year Plan’s major science programs — global brain science has entered a golden decade.
## Basic Brain Structure and Functional Regions
**Neurons**: the basic functional units of the brain, containing a cell body (Soma), dendrites (receiving signals), and axons (transmitting signals). Neurons communicate via synapses: electrical signals (action potentials) travel along axons, triggering neurotransmitter release at synaptic terminals — such as glutamate (excitatory), GABA (inhibitory), dopamine, and serotonin — which bind to receptors on downstream neurons.
**Cerebral Cortex**: divided into four major lobes — frontal (executive function, decision-making, working memory), parietal (spatial perception, sensory integration), temporal (language, long-term memory, face recognition), and occipital (visual processing). The cortex’s six-layer structure (Layers I-VI) is the most evolutionarily recent structure and the core of human cognitive superiority over other species.
**Default Mode Network (DMN)**: the neural network activated when the brain is “at rest” or introspecting, including medial prefrontal cortex, posterior cingulate cortex, and angular gyrus. The DMN relates to self-referential thinking, future imagination, and mental time travel. Meditation research finds that long-term meditators show significantly different DMN activity patterns, with less mind-wandering.
## Neurotransmitters and Cognitive Function
**Dopamine**: commonly misunderstood as the “pleasure molecule,” it actually functions as the core transmitter of **anticipation and motivation** — released heavily in response to reward *prediction* rather than reward *receipt*. The dopamine system regulates motivation, goal-directed behavior, and learning (prediction error signals in reinforcement learning). Dopamine depletion (as in Parkinson’s disease) causes motor disorders and motivational deficits.
**Serotonin**: regulates emotional stability, social behavior, sleep, and appetite. 90% of serotonin is produced in the gut (a “gut-brain axis” research hotspot). SSRI antidepressants (Prozac, Zoloft, etc.) raise synaptic serotonin by inhibiting reuptake.
See [Neuroplasticity Science Guide](https://sunqi.org/neuroplasticity-guide-en/) and [Nature Neuroscience journal](https://www.nature.com/neuro/).
