Head Position Indicator
Head Position Indicator - Related Videos
02:39
Indicators
0 Views •
2020
Certain organic substances change color in dilute solution when the hydronium ion concentration reaches a particular value. For example, phenolphthalein is a colorless substance in any aqueous solution with a hydronium ion concentration greater than 5.0 × 10−9 M (pH < 8.3). In more basic solutions where the hydronium ion concentration is less than 5.0 × 10−9 M (pH > 8.3), it is red or pink. Substances such as phenolphthalein, which can be used to determine the pH of a solution, are called...
15:16
Loading Drosophila Nerve Terminals with Calcium Indicators
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Cited by 17 •
2007
Calcium is a ubiquitous messenger in the nervous system, essential for triggering neurotransmitter release and changes in synaptic strength. Here we demonstrate a technique for loading Ca2+-indicators into Drosophila nerve terminals. We also demonstrate fabrication of the required apparatus and emphasize points critical for the technique's success.
08:17
Water Quality Analysis via Indicator Organisms
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2023
Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba -The University of Arizona Demonstrating Author: Luisa Ikner Water quality analysis monitors anthropogenic influences such as pollutants, nutrients, pathogens, and any other constituent that can impact the water’s integrity as a resource. Fecal contamination contributes microbial pathogens that threaten plant, animal, and human health with disease or illness. Increasing water demands and strict quality standards require that water...
02:39
Imaging the Mitochondrial Redox State in Primary Neurons Using a Ratiometric Indicator
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2025
Source: Katsalifis, A., et al. Live Imaging of the Mitochondrial Glutathione Redox State in Primary Neurons using a Ratiometric Indicator. J. Vis. Exp. (2021)This video demonstrates the imaging of mitochondrial redox state in primary neurons using a ratiometric fluorescent indicator. By applying two excitation wavelengths under a fluorescence microscope, the fluorescence intensity ratio is measured to assess mitochondrial oxidation. The protocol includes N-methyl-D-aspartate (NMDA) stimulation...
01:29
Law of Rational Indices
0 Views •
2026
The Law of rational indices is a fundamental principle in the field of crystallography. According to this law, the intercepts of a crystal face along the crystallographic axes (the three-dimensional axes along which a crystal is measured) can be expressed as either equivalent to the unit intercepts (a, b, c) or simple whole number multiples of them. These multiples are typically denoted as na, n'b, and n''c, where n, n', and n'' are simple whole numbers.To illustrate, consider a crystal with...
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The system infers orientation from the relative locations of light-emitting markers mounted at defined positions on the animal’s head. As the head rotates, the arrangement detected by the camera changes, allowing analysis to distinguish directional changes from simple translation. This geometric information helps relate neural responses to the animal’s heading during spatial or sensory tasks.
Head orientation and location describe different aspects of behavior. An animal can remain in one place while turning its head, or move through space without maintaining the same heading. Recording both variables lets researchers determine whether neural activity relates more closely to position, direction, movement, or combinations of these behavioral features.
It provides behavioral variables that can be aligned with electrophysiological or imaging recordings. Researchers can then examine how neural activity changes as an animal moves, turns, or occupies different parts of an environment. This supports investigations of spatial navigation, sensory processing, and motor control by linking recorded brain signals to measurable actions.
Continuous measurements of head location and orientation provide a behavioral reference for interpreting neural data collected during unconstrained movement. The same tracking framework can be applied across an experiment, improving measurement precision and reproducibility. These benefits are especially relevant when movement itself influences the neural activity under investigation.
Researchers mount light-emitting markers at defined positions on the animal’s head, place the animal within the camera’s tracking field, and detect the markers during behavior. The recorded relative marker locations are then used to calculate head direction, position, and movement over time. These behavioral measurements can subsequently be aligned with neural recordings.
Head-position tracking supports experiments on spatial navigation, sensory processing, motor control, and neural coding. In navigation studies, location and direction describe behavior in relation to space. In sensory and motor experiments, the same measurements help identify how neural activity corresponds to movement or orientation. The approach also supports studies combining freely moving behavior with electrophysiology or imaging.