DREADD-inactivation of dorsal CA1 pyramidal neurons in mice impairs retrieval of object and spatial memories.

The hippocampus, a medial temporal lobe brain region, is critical for the consolidation of information from short-term memory into long-term episodic memory and for spatial memory that enables navigation. Hippocampal damage in humans has been linked to amnesia and memory loss, characteristic of Alzheimer's disease and other dementias. Numerous studies indicate that the rodent hippocampus contributes significantly to long-term memory for spatial and nonspatial information.

Mice recognize 3D objects from recalled 2D pictures, support for picture-object equivalence.

Picture-object equivalence or recognizing a three-dimensional (3D) object after viewing a two-dimensional (2D) photograph of that object, is a higher-order form of visual cognition that may be beyond the perceptual ability of rodents. Behavioral and neurobiological mechanisms supporting picture-object equivalence are not well understood. We used a modified visual recognition memory task, reminiscent of those used for primates, to test whether picture-object equivalence extends to mice.

Object Recognition Memory: Distinct Yet Complementary Roles of the Mouse CA1 and Perirhinal Cortex.

While the essential contribution of the hippocampus to spatial memory is well established, object recognition memory has been traditionally attributed to the perirhinal cortex (PRh). However, the results of several studies indicate that under specific procedural conditions, temporary or permanent lesions of the hippocampus affect object memory processes as measured in the Spontaneous Object Recognition (SOR) task. The PRh and hippocampus are considered to contribute distinctly to object recognition memory based on memory strength.

Effect of a hallucinogenic serotonin 5-HT receptor agonist on visually guided, hippocampal-dependent spatial cognition in C57BL/6J mice.

By acting on serotonin 5-HT receptors (5-HT Rs), serotonergic psychedelic drugs induce perceptual and visual hallucinations by increasing neuronal excitability and altering visual-evoked neuronal responses. The present study was designed to examine whether the perceptual alterations induced by a serotonergic psychedelic drug would affect the integrity of hippocampal-dependent, visually guided spatial cognition. phenylalkylamine hallucinogen TCB-2 is a selective agonist of 5-HT Rs.

Examination of the hippocampal contribution to serotonin 5-HT2A receptor-mediated facilitation of object memory in C57BL/6J mice.

The rodent hippocampus supports non-spatial object memory. Serotonin 5-HT2A receptors (5-HT2AR) are widely expressed throughout the hippocampus. We previously demonstrated that the activation of 5-HT2ARs enhanced the strength of object memory assessed 24 h after a limited (i.