Question 1

Why do neuroscientists use primary neuronal cultures instead of studying the whole brain?

Accepted Answer

The brain's complexity makes it difficult to manipulate and observe individual neurons directly. Primary neuronal cultures provide a simpler, controllable system where neurons are easily accessible for experimental tools and techniques. This allows researchers to study specific cellular phenomena like protein trafficking and electrophysiology without the complications of intact brain tissue.

Question 2

What are the main steps involved in preparing primary neuronal cultures?

Accepted Answer

Primary neuronal culture preparation involves four major steps: dissection of nervous system tissue from an organism, dissociation into single cells using enzymes and trituration, plating cells in culture media on treated surfaces, and maintenance through regular media replacement. Each step is critical to ensure cell viability and successful culture growth in a sterile, warm incubator environment.

Question 3

How does dissociation break down tissue into individual neurons?

Accepted Answer

Dissociation uses both chemical and mechanical methods. First, proteolytic enzymes like trypsin or papain digest the extracellular matrix proteins binding cells together. After enzyme removal, trituration—passing tissue through a pipet multiple times—physically separates cells into a single cell suspension. Trypan blue staining then assesses cell viability before plating.

Question 4

Why must glass coverslips be treated before plating neurons?

Accepted Answer

Neurons cannot grow directly on untreated glass surfaces. Coverslips are pretreated to improve cell attachment and growth through coating with synthetic extracellular matrix proteins like poly-lysine and laminin, or by acid etching to roughen the surface. These treatments create a more favorable substrate for neuronal adhesion and development.

Question 5

How can genetic manipulation be used to study protein trafficking in cultured neurons?

Accepted Answer

Neurons are transfected with DNA encoding a protein of interest fused to a fluorescent protein like green fluorescent protein (GFP). Live imaging then tracks the movement and localization of the fluorescently-tagged protein throughout the neuron. This approach reveals how proteins such as neurotransmitter receptors are trafficked to specific cellular structures.

Question 6

What makes primary neuronal cultures ideal for electrophysiology experiments?

Accepted Answer

The single layer of neurons in culture allows individual cells to be easily targeted with microelectrodes for measuring electrical activity. Manipulations like pharmacological treatments are quickly and evenly applied across the culture. The patch clamp electrophysiology principle applications enable researchers to measure how test compounds affect single neuron activity in a controlled environment.

Question 7

What tissue sources can be used to create different types of primary neuronal cultures?

Accepted Answer

Various nervous system tissues from multiple developmental stages can be cultured. Specific brain regions like the cerebellum, cortex, and hippocampus produce different neuronal types. The spinal cord and peripheral nervous system components such as dorsal root ganglia can also be dissected and cultured. Embryos and perinatal tissue are preferred because immature brain cells are less susceptible to damage.

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