DOT 3

• Small subcortical lesions are commonly made by passing radio-frequency current (high-frequency current) through the target tissue from the tip of a stereotaxically positioned electrode.

  RADIO-FREQUENCY LESIONS
• Sectioning (cutting) is used to eliminate conduction in a nerve or tract. A tiny, well-placed cut can unambiguously accomplish this task without producing extensive damage to surrounding tissue.

  KNIFE CUTS.
• This is an useful alternatives to destructive lesions. A method for temporarily eliminating the activity in a particular area of the brain while tests are being conducted.

  Reversible lesions
• lesions restricted to one half of the brain

  unilateral lesions
• lesions involving both sides of the brain

  bilateral lesions
• This method provides a moment-by-moment record of the graded fluctuations in one neuron’s membrane potential.

  INTRACELLULAR UNIT RECORDING
• This can record the activity of a neuron through a microelectrode whose tip is positioned in the extracellular fluid next to it—each time the neuron fires, there is an electrical disturbance and a blip is recorded at the electrode tip.

  EXTRACELLULAR UNIT RECORDING.
• This can provides a record of the firing of a neuron but no information about the neuron’s membrane potential.

  extracellular unit recording
• it picks up signals from many neurons, and slight shifts in its position due to movement of the subject have little effect on the overall signal.

  multiple-unit recording
• Drugs can be administered in small amounts through a fine, hollow tube, called a ___________.

  cannula
• Entails placing an animal that has been injected with radioactive 2-DG in a test situation in which it engages in an activity of interest.

  2-DEOXYGLUCOSE TECHNIQUE
• brains are coated with a photographic emulsion, stored in the dark for a few days, and then developed much like film.

  autoradiography
• A method of measuring the extracellular concentration of specific neurochemicals in behaving animals (most other techniques for measuring neurochemicals require that the subjects be killed so that tissue can be extracted).

  Cerebral dialysis
• a procedure for locating particular neuroproteins in the brain by labeling their antibodies with a dye or radioactive element and then exposing slices of brain tissue to the labeled antibodies.

  Immunocytochemistry
• This technique takes advantage of the fact that all peptides and proteins are transcribed from sequences of nucleotide bases on strands of messenger RNA (mRNA). The nucleotide base sequences that direct the synthesis of many neuroproteins have been identified, and hybrid strands of mRNA with the complementary base sequences have been artificially created.

  in situ hybridization
• Procedures for creating organisms that lack a particular gene under investigation

  Gene knockout techniques
• Pathological genes from human cells can be inserted in other animals such as mice.

  gene knockin techniques
• allow researchers to edit genes at a particular time during development

  gene editing techniques
• Cas9 (a protein) is linked to a strand of RNA called the guide-RNA. The guide-RNA is made up of a sequence of nucleotide bases that are complementary to one or more strands of DNA. Once the guide-RNA and Cas9 are linked, it can be integrated into a virus. The virus can then be injected into an animal—either peripherally if one wants to edit the genome of the whole organism, or intracranially into a specific brain region if one wants to observe the focal effects of editing a gene in cells in that brain region.

  CRISPR/Cas9 method
• a protein that exhibits bright green fluorescence when exposed to blue light.

  Green fluorescent protein (GFP)