Related Experiment Video
Updated: Jun 2, 2026
06:32
Quadruple Immunostaining of the Olfactory Bulb for Visualization of Olfactory Sensory Axon Molecular Identity Codes
Published on: June 5, 2017
Lateral Connectivity in the Olfactory Bulb is Sparse and Segregated.
David H Kim1, Matthew E Phillips, Andrew Y Chang
1Department of Neurobiology, Yale University School of Medicine New Haven, CT, USA.
Frontiers in Neural Circuits
|May 12, 2011
Summary
Lateral connections in the olfactory bulb involve sparse inhibitory granule cells (GCs) organized in clusters. These GCs provide segregated inhibitory inputs to neighboring mitral and tufted cells, refining olfactory processing.
Area of Science:
- Neuroscience
- Olfactory System Research
- Cellular Connectivity
Background:
- Olfactory bulb lateral connections were traditionally viewed as center-surround inhibitory.
- Recent findings suggest sparse, distributed inhibitory granule cell (GC) interactions in columnar clusters.
- The interconnection of these distributed GC clusters remains poorly understood.
Purpose of the Study:
- To investigate the connectivity between mitral/tufted cells and GCs in the olfactory bulb.
- To elucidate how these distributed GC clusters are interconnected through lateral connections.
- To map the specific inhibitory inputs onto neighboring olfactory bulb neurons.
Main Methods:
- Utilized transsynaptic tracing viruses with distinct fluorescent proteins (green and red).
- Injected viruses into separate sites within the glomerular layer of the olfactory bulb.
- Performed dual injections into the olfactory cortex to compare connectivity patterns.
Main Results:
- Transsynaptic spread revealed sparse GCs, with red or green labeling tending to segregate within columns.
- A higher-than-chance incidence of co-labeled cells was observed, indicating overlap in GC populations.
- Similar segregation patterns were found in dual injections into the olfactory cortex.
Conclusions:
- Neighboring mitral and tufted cells receive inhibitory inputs from distinct, segregated subsets of GCs.
- This segregated GC organization enables specific and discontinuous lateral inhibition within the olfactory bulb.
- The findings refine the understanding of olfactory information processing and lateral network organization.
Related Concept Videos
01:25Olfaction
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...
The olfactory receptors are embedded in the cilia of the...
01:03Olfactory 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...
01:20Physiology 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...
The olfactory...
01:27Diencephalon: Thalamus and Information Relay
The thalamus, often called “the gateway to the cerebral cortex,” is vital in processing and directing sensory and motor signals throughout the brain. Almost all inputs destined for the cerebral cortex, except for olfactory signals, are relayed through the thalamus. The thalamus is a sophisticated relay station, channeling information from various brain regions to the cerebral cortex, as well as a filter, prioritizing certain signals over others based on current physiological states or needs.
01:15Functional Brain Systems: Limbic System
The limbic system, often called the "emotional brain," is a complex set of structures located deep within the brain. The intricate network of the limbic system supports a wide range of psychological functions, from emotional regulation to memory formation and sensory processing. This functional brain region encompasses specific parts of the diencephalon and the cerebrum, integrating the higher mental functions of the cerebral cortex with the primitive emotional responses of the deep brain...
01:30Diencephalon: Anatomical Regions
The diencephalon, etymologically translated as 'through brain,' plays an integral role as the conduit between the cerebrum and the vast extent of the nervous system. However, the olfactory system is an exception, as it interfaces directly with the cerebrum. The diencephalon, deeply ensconced beneath the cerebrum, primarily consists of three paired structures — the thalamus, hypothalamus, and epithelamus. It also includes accessory structures such as the subthalamus, which houses the subthalamic...