Related Experiment Video

Updated: May 18, 2026

A Lateralized Odor Learning Model in Neonatal Rats for Dissecting Neural Circuitry Underpinning Memory Formation
10:42

A Lateralized Odor Learning Model in Neonatal Rats for Dissecting Neural Circuitry Underpinning Memory Formation

Published on: August 18, 2014

Blocking muscarinic receptors in the olfactory bulb impairs performance on an olfactory short-term memory task

Sasha Devore1, Laura C Manella, Christiane Linster

  • 1Computational Physiology Laboratory, Department of Neurobiology and Behavior, Cornell University Ithaca, NY, USA.

Frontiers in Behavioral Neuroscience
|September 14, 2012
PubMed

Insights

Cholinergic signaling in the olfactory bulb (OB) impacts odor discrimination. High doses of scopolamine disrupt olfactory task performance, indicating muscarinic signaling is crucial for OB function.

Area of Science:

  • Neuroscience
  • Olfactory system research
  • Cholinergic system studies

Background:

  • Cholinergic inputs are linked to attention and top-down processing in cortical networks.
  • Cholinergic signaling in the main olfactory bulb (OB) influences neural and behavioral odor discrimination.
  • Muscarinic receptor blockade impairs olfactory perception under demanding conditions.

Purpose of the Study:

  • To investigate the role of muscarinic signaling in the OB using a behavioral olfactory task.
  • To determine the effects of scopolamine, a muscarinic antagonist, on olfactory memory and task performance.

Main Methods:

  • Developed an olfactory delayed match-to-sample task utilizing a digging-based behavioral paradigm in rats.
  • Administered bilateral infusions of varying scopolamine dosages (7.6 mM, 22.8 mM, 38 mM) into the OB.
  • Assessed task performance across different delay durations (0-100 s).

Main Results:

  • Rats demonstrated robust short-term odor memory (10-100 s).
  • High-dose scopolamine (38 mM) significantly impaired performance on the olfactory match-to-sample task at all delay intervals.
  • Lower scopolamine dosages (7.6 mM and 22.8 mM) did not produce measurable effects on task performance.

Conclusions:

  • Muscarinic signaling within the OB is essential for the general execution of olfactory match-to-sample tasks, even without a delay.
  • These findings highlight the significant role of muscarinic pathways in olfactory bulb processing and odor-guided behavior.
Keywords:
acetylcholinedelayed match-to-sampleolfactionolfactory bulbscopolamine

More Related Videos

The Double-H Maze: A Robust Behavioral Test for Learning and Memory in Rodents09:01

The Double-H Maze: A Robust Behavioral Test for Learning and Memory in Rodents

Published on: July 8, 2015

Related Concept Videos

Olfactory Receptors: Location and Structure01:03

Olfactory Receptors: Location and Structure

The process of olfaction, also known as the sense of smell, is a sophisticated chemical response system. The specialized sensory neurons that facilitate this process, known as olfactory receptor neurons, are situated in an upper segment of the nasal cavity, known as the olfactory epithelium. Olfactory sensory neurons are bipolar, with their dendrites extending from the epithelium's apex into the mucus that lines the nasal cavity. Airborne molecules, when inhaled, traverse the olfactory...
Olfaction01:25

Olfaction

The sense of smell is achieved through the activities of the olfactory system. It starts when an airborne odorant enters the nasal cavity and reaches olfactory epithelium (OE). The OE is protected by a thin layer of mucus, which also serves the purpose of dissolving more complex compounds into simpler chemical odorants. The size of the OE and the density of sensory neurons varies among species; in humans, the OE is only about 9-10 cm2.
The olfactory receptors are embedded in the cilia of the...
Cholinergic Antagonists: Pharmacological Actions01:28

Cholinergic Antagonists: Pharmacological Actions

Antimuscarinic drugs block muscarinic receptors in multiple systems, including the gut, eye, smooth muscles, respiratory tract, cardiovascular, and central nervous systems. They produce similar effects with varying selectivity depending on the specific agent and tissue. Here are the key pharmacological actions of antimuscarinics:
Gastrointestinal Effects: Antimuscarinics reduce gut contractions, increase gastric emptying, and slow intestinal transit. They partly inhibit gastric acid secretion...
Physiology of Smell and Olfactory Pathway01:20

Physiology of Smell and Olfactory Pathway

Humans detect odors with the help of specialized cells located in the upper part of the nasal cavity, called olfactory receptor neurons (ORNs). ORNs possess hair-like structures called cilia, which are receptive to sensations from the inhaled air. When an odorant molecule binds to a specific receptor on the cell of the cilia, it leads to a series of events that ultimately cause the ORN to send electrical signals to the olfactory bulb in the brain through the olfactory nerves.
The olfactory...
Cholinergic Antagonists: Therapeutic Uses01:26

Cholinergic Antagonists: Therapeutic Uses

Antimuscarinic drugs have various therapeutic applications by inhibiting parasympathetic stimulation in different systems. Here are the key therapeutic uses of antimuscarinics:    
Respiratory Tract: Ipratropium, aclidinium, and tiotropium treat asthma, chronic bronchitis, and chronic obstructive pulmonary disease (COPD). They protect against bronchoconstriction caused by irritants like cigarette smoke, sulfur dioxide, and ozone. They also help reduce nasopharyngeal secretions in common...