page_title: Behavioral neuroscience
section_title: Disabling or decreasing neural function
hierarchical_section_title: Behavioral neuroscience / Research methods / Disabling or decreasing neural function
caption_attribution_description: English: Description in article for the original image: Figure 5. FLAIR (3T) and GRE phase (7T) images of a patient with active relapsing-remitting MS. FLAIR images show numerous white matter MS lesions of which 2 are magnified (inset, red arrows). Phase imaging at 7T phase/GRE reveals a hypointense ring corresponding with one lesion on FLAIR. The other lesion is not visible on 7T GRE (inset, arrows). After cropping, only the GRE phase brain scan (right of the original image) was left. Other info copied from article by uploader of file: Gradient-echo (GRE) phase imaging at ultra-highfield MRI is highly sensitive for iron. A number of GRE studies with MS patients and autoptic MS tissue, including our own have demonstrated that iron accumulates in white matter and cortical lesions.
context_page_description: Behavioral neuroscience, also known as biological psychology, biopsychology, or psychobiology, is the application of the principles of biology to the study of physiological, genetic, and developmental mechanisms of behavior in humans and other animals.
context_section_description: Lesions – A classic method in which a brain-region of interest is naturally or intentionally destroyed to observe any resulting changes such as degraded or enhanced performance on some behavioral measure. Lesions can be placed with relatively high accuracy "Thanks to a variety of brain 'atlases' which provide a map of brain regions in 3-dimensional "stereotactic coordinates.
  Surgical lesions –  Neural tissue is destroyed by removing it surgically.
  Electrolytic lesions – Neural tissue is destroyed through the application of electrical shock trauma.
  Chemical lesions – Neural tissue is destroyed by the infusion of a neurotoxin.
  Temporary lesions – Neural tissue is temporarily disabled by cooling or by the use of anesthetics such as tetrodotoxin.
  Transcranial magnetic stimulation – A new technique usually used with human subjects in which a magnetic coil applied to the scalp causes unsystematic electrical activity in nearby cortical neurons which can be experimentally analyzed as a functional lesion.
  Synthetic ligand injection – A receptor activated solely by a synthetic ligand (RASSL) or Designer Receptor Exclusively Activated by Designer Drugs (DREADD), permits spatial and temporal control of G protein signaling in vivo. These systems utilize G protein-coupled receptors (GPCR) engineered to respond exclusively to synthetic small molecules ligands, like clozapine N-oxide (CNO), and not to their natural ligand(s).  RASSL's represent a GPCR-based chemogenetic tool. These synthetic ligands upon activation can decrease neural function by G-protein activation. This can with Potassium attenuating neural activity.
  Psychopharmacological manipulations – A chemical receptor antagonist induces neural activity by interfering with neurotransmission. Antagonists can be delivered systemically (such as by intravenous injection) or locally (intracerebrally) during a surgical procedure into the ventricles or into specific brain structures.  For example, NMDA antagonist AP5 has been shown to inhibit the initiation of long term potentiation of excitatory synaptic transmission (in rodent fear conditioning) which is believed to be a vital mechanism in learning and memory.
  Optogenetic inhibition – A light activated inhibitory protein is expressed in cells of interest. Powerful millisecond timescale neuronal inhibition is instigated upon stimulation by the appropriate frequency of light delivered via fiber optics or implanted LEDs in the case of vertebrates, or via external illumination for small, sufficiently translucent invertebrates. Bacterial Halorhodopsins or Proton pumps are the two classes of proteins used for inhibitory optogenetics, achieving inhibition by increasing cytoplasmic levels of halides (Cl⁻
  ) or decreasing the cytoplasmic concentration of protons, respectively.
caption: The part of the picture emphasized shows the lesion in the brain. This type of lesion can be removed through surgery.
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