The test provides a method for evaluating an animal’s entorhinal cortex, where grid cells integrate information from the hippocampus and the pre- and post-subiculum (where head direction cells are located). We record latency time to find the escape and errors of commission (entry into blind alleys). The test is conducted in complete darkness (monitored with an infrared light emitter and camera) to eliminate distal cues, thus testing the animal’s “sense of direction” or ability to navigate using route-based egocentric cues (i.e., internal cues). This uses a labyrinthine maze with nine T-shaped cul-de-sacs branching from a central (but circuitous) channel leading from the start to the goal. We also have experience using a variety of other agents for this test. We typically test animals using indirect dopaminergic agonists, specific dopamine D1 and D2 agonists and antagonists, cholinergic-muscarinic antagonists and glutamatergic-NMDA receptor antagonists. Typically, the test involves familiarizing the test animal with a test chamber, and then observing changes to the animal’s behavior after it is injected with one of a variety of drug challenges. This test can be modified to fit a PI’s specific needs.
![shuttlebox on any-maze shuttlebox on any-maze](https://y9s5q4c4.stackpathcdn.com/maze/wp-content/uploads/2019/01/Alley_maze_01__00012.jpg)
Activity with Pharmacological Challenge.A typical test requires 20-25 trials/day for 5 days to obtain adequate learning. Two-way active avoidance is a classically conditioned response where the signal is the conditioned stimulus (CS), the shock is the unconditioned stimulus (US), escape is similar to an unconditioned response (UR), and avoidance is a conditioned response (CR). If the animal crosses to the opposite side from where they start, they avoid the shock if they wait until the warning period is over, the shock is activated and they must escape to the opposite side.
![shuttlebox on any-maze shuttlebox on any-maze](https://www.any-maze.com/wp-content/uploads/2020/07/video_cover_v3.png)
ASR and PPI test methods and responses are nearly identical in humans and rodents, offering homologous comparisons across species.Īctive/two-way/shuttle box avoidance test using the San Diego Instruments two-sided Gemini System to test the ability of animals to learn to respond to a warning signal (light, tone, or both) that the grid floor is about to deliver a mild aversive stimulus (foot shock).
![shuttlebox on any-maze shuttlebox on any-maze](https://y9s5q4c4.stackpathcdn.com/maze/wp-content/uploads/2015/11/MazeEngineers_AutomatedMazeGraphics_Rev_DownwardFacingDoors.png)
PPI is abnormal in several human disorders, such as schizophrenia and major depression. We also test for pre-pulse inhibition (PPI), a well-established measure for testing sensorimotor gating. We use the San Diego Instruments SR Apparatus for these tests. The Acoustic (ASR) and Tactile Startle Response (TSR) are well-established tests for evaluating the complex brainstem-mediated reflex pathway.