Reading Notes and Open Questions on 'Mind Homeland: Neuroscience and Brain Science'

We are capable of perception and movement, learning and memory, and endowed with the faculties of language, thought, and problem-solving—all stemming from the organ under 1.5 liters in volume within our skull: the brain.

The brain and nervous system constitute the most intricate system in the natural world and represent an ultimate scientific fortress that humanity has yet to conquer. The splendid achievements of 20th-century scientists exploring the brain and nervous system are detailed throughout this volume.

Key Excerpts from ‘Mind Homeland: Neuroscience and Brain Science’

Along every sensory or motor “wire” (nerve fiber), the transmission of signals is strictly unidirectional. (P. 15)

Question: What mechanism enforces this unidirectionality? Is it analogous to an electrical potential difference or a hydraulic pressure head?

Around 1900, the research of Ramón y Cajal established that nerve cells are the fundamental structural and functional units of the nervous system and brain, giving birth to the Neuron Doctrine (how neurons connect with one another). Over the subsequent century, neuroscientists investigated molecular, cellular, systems, behavioral, and cognitive dimensions, respectively establishing molecular neurobiology, cellular neurobiology, systems neurobiology, behavioral neurobiology, and cognitive neurobiology. (P. 18)

Electrophysiological techniques (such as patch-clamp) and molecular biology methods (such as recombinant DNA technology) have granted us a far deeper understanding of the fundamental units of neural signal generation and propagation: the structure, functional properties, and operational mechanisms of ion channels. (P. 19)

Question: Even as modern research has reached cellular and molecular levels, how does this machinery collectively synthesize intelligence?

Camillo Golgi developed histological staining methods for nervous tissue (silver nitrate staining) and utilized them to study the architecture of the central nervous system (CNS). (P. 22)

Question: Do we currently possess in vivo neural staining or imaging techniques capable of visualizing living organisms?

Nerve fibers are categorized into multiple functional types, which are frequently intermingled and vary substantially in length and structure. (P. 23)

Question: If nerve fibers with different functions are physically interwoven, do humans possess the capacity to dynamically modulate and utilize distinct types of nerve fibers?

Ramón y Cajal formulated the Neuron Doctrine, stating that the nervous system consists of discrete individual neurons, each enveloped by an outer membrane that isolates it from its surroundings. The neuron is the foundational signaling unit of the nervous system. Subsequently, Ramón y Cajal also pioneered the sublimate-gold chloride staining technique. (P. 26)

Ramón y Cajal showed that a neuron comprises a cell body (soma), dendrites, an axon, and numerous axon terminals, exhibiting dynamic polarity where dendrites receive input signals and the axon delivers outputs. (P. 27)

An identical stimulus may trigger opposite responses across different neurons or even within the same neuron under differing physiological conditions. Neurons possess the capability to integrate distinct nerve impulses generated concurrently or sequentially. When these concurrent or consecutive impulses partially or completely cancel each other out, the dominant signal determines the final output response. (P. 33)

An external stimulus requires a specific threshold to elicit a nerve impulse; once the stimulus intensity exceeds this threshold, an action potential is triggered. The amplitude of this action potential remains constant regardless of any further increase in stimulus intensity—this is known as the all-or-none law. (P. 36)

Question: How is this physiological threshold determined and regulated?

Andrew F. Huxley discovered that nerve conduction in myelinated nerve fibers is discontinuous and occurs via saltatory conduction. (P. 47)

Taking the heart as an illustration, sympathetic pathways convey impulses that accelerate heart rate, whereas parasympathetic pathways transmit impulses that decelerate it. (P. 60)

G proteins require GTP binding to exert physiological functions and act as molecular transducers. (P. 83)

Nerve Growth Factor (NGF) and Epidermal Growth Factor (EGF). (P. 125)

Question: Could the evolutionary origin and emergence of these growth factors be linked to broader evolutionary adaptations?

Prion protein, originally a native constituent of human white blood cells, exhibits two distinct conformational folding states (PrPc and PrPSc), the latter being infectious and transmissible (e.g., Bovine Spongiform Encephalopathy / Mad Cow Disease). (P. 151)

Innovation, development, and refinement of research methodologies and investigative tools are paramount. The judicious selection and utilization of appropriate experimental materials or model organisms represent vital prerequisites for scientific breakthrough. Ingenious experimental design, perseverance, and acute discernment are critical determinants of discovery. Seamless cross-disciplinary collaboration among scientists with diverse knowledge backgrounds accelerates the revelation of scientific truth. (P. 165)

Bibliographic Information: ‘Mind Homeland: Neuroscience and Brain Science’

• Title: Mind Homeland: Neuroscience and Brain Science (心智家園─神經與腦科學)
• Author: Li Baoming (李葆明)
• ISBN: 957-776-676-5