Locomotor activity is automatically quantified by computer using Tru-Scan photobeam-based open field activity chambers. Horizontal, vertical, and stereotyped movements is measured. This behavior is increased by stimulating drugs as well as active strains or phenotypes. It is also often used as a control assay to ensure that motor function is intact when a learning and memory deficit is apparent in a cognition task that relies on motor function. CleverSys automated behavioral video tracking system can be used as an alternative method when a lower baseline level of activity is desirable.
Example data can be seen below:
Motor coordination and balance is a common measured for neurodegenerative and other disorders that affect motor function. This is conducted using a rotarod apparatus that requires limb coordination. For an example apparatus, see here:
Gait analysis can be used to measure limb asymmetry. This is conducted by examining backwards movement along a platform that requires adjusting steps to maintain balance on the platform. The test is repeated on the other side to assess both contralateral and ipsilateral steps. Gait analysis can also be used to measure stride length. For this procedure, rodent footprints are recorded as they walk freely through a straight runway. The distance between the hind paws for the ipsilateral and contralateral stride are recorded.
For an example procedure, see:
Chitre NM, Wood BJ, Ray A, Moniri NH, Murnane KS (2020) Docosahexaenoic acid protects motor function and increases dopamine synthesis in a rat model of Parkinson's disease via mechanisms associated with increased protein kinase activity in the striatum. Neuropharmacology 167: 107976. PMID: 32001239
Conditioned Place Preference
Conditioned place preference is a well-accepted procedure for assessing the positive appetitive conditioned effects of drugs of abuse. Conditioned place preference is conducted in a two-sided shuttle box. These compartments are differentiated through a series of tactile and visual cues (vertical vs. horizontal stripes). Drugs are repeatedly paired with one side of the chamber until a preference is established.
For an example protocol, see:
Oppong-Damoah A, Curry KE, Blough BE, Rice KC, Murnane KS (2019) Effects of the synthetic psychedelic 2,5-dimethoxy-4-iodoamphetamine (DOI) on ethanol consumption and place conditioning in male mice. Psychopharmacology (Berl) 236: 3567-3578. PMID: 31309240
The Y-maze assay of spontaneous alternations is used to assess spatial working memory. The subject is placed in a three arm maze and allowed to explore all arms freely. Preference for entry in novel arms over the familiar arms is interpreted as a novelty preference inherent in rodents, while lack of discrimination between novel and familiar arms is interpreted as impaired location recognition. The BCL records behavior in this assay using automated video tracking.
For an example procedure, see:
Lindsey LP, Daphney CM, Oppong-Damoah A, Uchakin PN, Abney SE, Uchakina ON, Khusial RD, Akil A, Murnane KS (2019) The cannabinoid receptor 2 agonist, beta-caryophyllene, improves working memory and reduces circulating levels of specific proinflammatory cytokines in aged male mice. Behav Brain Res 372: 112012. PMID: 31173795
Novel Object Recognition
The novel object recognition (NOR) test is also a measure of recognition memory that is based on the spontaneous tendency of rodents to spend more time exploring a novel object than a familiar object. The animal is initially habituated to a test arena and one day later, is presented with two similar objects that are matched for size and texture during an initial familiarization session, and then one of the two objects is replaced by a new object during a second test session. The difference in time spent exploring the novel and familiar objects is used for recognition memory.
The Barnes maze is a simplified spatial learning task similar to the Morris water maze that can be used to assess spatial learning and memory. In comparison to the Morris water maze, the Barnes maze employs less stressful negative reinforcement (e.g., escape form water), which makes it a better choice for animals with compromised function. This maze consists of a circular table with circular holes around the circumference. The goal is for the animal to reach the box that is positioned beneath one of the holes with the aid of visual cues. Trials are recorded with the CleverSys video tracking system and measured for escape latency, strategy, distance moved, and velocity.
The passive avoidance test has been argued to measure aspects of both procedural and declarative memory. Testing is conducted in a shuttle box with two separate compartments (one that is dark and one that is brightly illuminated) separated by a square opening. When placed in the illuminated chamber, nocturnal animals rapidly cross over to the dark chamber. The animal is then trained to avoid that side of the box. An increased latency to cross in a subsequent post-conditioning session is used as an index of memory.
For an example protocol, see:
Murnane KS, Perrine SA, Finton BJ, Galloway MP, Howell LL, and Fantegrossi WE (2012) Effects of exposure to amphetamine derivatives on passive avoidance performance and the central levels of monoamines and their metabolites in mice: correlations between behavior and neurochemistry. Psychopharmacology 220(3):495-508. PMID: 21993877
Delayed Non-Match to Position
The Delayed Non-Match to Position has been used to measure flexible decision making. This can be conducted using either a T-maze that is similar to the Y-maze or by using operant behavior. All experiments in the T-maze will be video tracked and analyzed using the Topscan video tracking system. Operant behavior will be automatically recorded in operant chambers that are identical to those used for self-administration. Strengths of this procedure are that it allows for within session assessments of memory load (from easy to difficult), provides a daily record of cognitive performance and decline, and is based on procedures widely used for neuropsychiatric assessments of human patients. Its primary disadvantages is that it requires extensive training.
In the open field test, exploration in the open field can be used to measure anxiety. This test is based on the inner conflict between exploration and the avoidance of novel environments/stimuli (e.g., open field). Thigmotaxis is automatically quantified by computer using Tru-Scan photobeam-based open field activity chambers.