Bilateral Alignment of Receptive Fields in the Olfactory Cortex

Grimaud, Julien; Dorrell, William; Pehlevan, Cengiz; Murthy, Venkatesh N.

doi:10.1101/2020.02.24.960922

Cited by 5 publications

(18 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result is inline with the indirect pathway. However, a very recent study found that a substential number of AON and aPC neurons responded to ipsi-and contralateral odors and that these responses are of similar magnitute 87 . This similarity in bilateral odor receptive fields suggests that AON and aPC neurons receive contra-input through the direct pathway.…”

Section: Functional Bilateral Connectivitymentioning

confidence: 97%

See 1 more Smart Citation

Bilateral and unilateral odor processing and odor perception

2020

View full text Add to dashboard Cite

Imagine smelling a novel perfume with only one nostril and then smelling it again with the other nostril. Clearly, you can tell that it is the same perfume both times. This simple experiment demonstrates that odor information is shared across both hemispheres to enable perceptual unity. In many sensory systems, perceptual unity is believed to be mediated by inter-hemispheric connections between iso-functional cortical regions. However, in the olfactory system, the underlying neural mechanisms that enable this coordination are unclear because the two olfactory cortices are not topographically organized and do not seem to have homotypic inter-hemispheric mapping. This review presents recent advances in determining which aspects of odor information are processed unilaterally or bilaterally, and how odor information is shared across the two hemispheres. We argue that understanding the mechanisms of inter-hemispheric coordination can provide valuable insights that are hard to achieve when focusing on one hemisphere alone. I n the early 1940s, patients suffering from severe untreatable epileptic seizures underwent a pioneering operation in which their corpus callosum was severed. While this mitigated the epilepsy syndromes, it generated strange phenomena: each hemisphere seemed to have its own separate perception, concepts, and even actions. When such split-brain patients were shown an image of an object in their left visual field, they could not vocally name what they had seen. This is because information about the image seen in the left visual field is sent only to the right side of the brain, while the speech-control center is usually on the left side of the brain. Nonetheless, patients could pick up the correct object with their left hand because it is controlled by the right hemisphere 1. Some of the surgery-induced deficits improved over time, but they illustrate one important principle: the fibers that interconnect the hemispheres are responsible for transferring information from one side to the other. These connecting fibers may be required to achieve perceptual unity, at least in some sensory modalities. But how is perceptual unity achieved? There are several possible ways to achieve perceptual unity in the healthy brain. One way is to ensure that sensory information is transmitted to both hemispheres directly from the sensory organs. This is how auditory information is unified across hemispheres: information from both ears converges to the left and the right Superior Olivary

show abstract

Section: Functional Bilateral Connectivitymentioning

confidence: 97%

“…3). The exisitance of extensive bilateral connections suggests that the direct pathway plays an important role in bilateral information transfer 87 . Random connectivity between OB and OC neurons 10-12 makes the task of achieving perceptual unity more difficult.…”

Section: How Is Perceptual Unity Achieved In Olfaction?mentioning

confidence: 99%

Bilateral and unilateral odor processing and odor perception

2020

View full text Add to dashboard Cite

show abstract

“…Early work in anesthetized rats has shown that odor responses in PC can be nostril-specific 21 , suggesting that a given odorant may activate different neurons across PC depending on stimulus laterality. Recent work in awake mice has found that neural population responses to ipsilateral versus contralateral odorants were indeed distinguishable but remained highly correlated 22 . Our results are consistent with these rodent studies, and together suggest that ipsilateral and contralateral odors activate partially overlapping but distinct ensembles of neurons that ultimately give rise to similar yet distinguishable response dynamics at the population level.…”

Section: Discussionmentioning

confidence: 99%

“…These findings raise the intriguing possibility that the same odor delivered to the ipsilateral versus contralateral nostril may ultimately elicit similar representations that are merely shifted in time. Indeed, work in rodents has shown that PC responses to ipsilateral versus contralateral odors are correlated at the neural population level 22 .…”

Section: Ipsilateral and Contralateral Odors Elicit Similar Yet Disti...mentioning

confidence: 99%

Odor representations from the two nostrils are temporally segregated in human piriform cortex

Dikecligil

Yang

Sanghani

et al. 2023

Preprint

View full text Add to dashboard Cite

The human olfactory system has two discrete channels of sensory input, arising from olfactory epithelia housed in the left and right nostrils. Here, we asked whether primary olfactory cortex (piriform cortex, PC) encodes odor information arising from the two nostrils as unified or distinct stimuli. We recorded intracranial EEG signals directly from PC while human subjects participated in an odor identification task where odors were delivered to the left, right, or both nostrils. We analyzed the time-course of odor-identity coding using machine learning approaches, and found that odor inputs from the ipsilateral nostril are encoded ~480 ms faster than odor inputs from the contralateral nostril. This temporal staggering across the nostrils gave rise to two non-overlapping epochs of odor coding within a single sniff when odors were sampled through both nostrils. These findings reveal that PC maintains distinct representations from each nostril by temporally segregating odor information, highlighting an olfactory coding scheme at the cortical level that can parse odor information across nostrils within a single sniff.

show abstract

“…In these models, the random connectivity is a necessary basis for learning arbitrary stimulus combinations during an individual’s lifetime. It remains, however, unclear whether random connectivity alone can account for specific olfactory percepts and actions, reproducible between individuals 30, 53 . Furthermore, identifying structure in the connectivity of the olfactory system has been impeded by the scarcity of single cell connectivity data available.…”

Section: Mainmentioning

confidence: 99%

Wiring logic of the early rodent olfactory system revealed by high-throughput sequencing of single neuron projections

Chen

Başerdem

et al. 2021

Preprint

View full text Add to dashboard Cite

The structure of neuronal connectivity often provides insights into the relevant stimulus features, such as spatial location, orientation, sound frequency, etc1-6. The olfactory system, however, appears to lack structured connectivity as suggested by reports of broad and distributed connections both from the olfactory bulb to the piriform cortex7-22 and within the cortex23-25. These studies have inspired computational models of circuit function that rely on random connectivity26-33. It remains, nonetheless, unclear whether the olfactory connectivity contains spatial structure. Here, we use high throughput anatomical methods (MAPseq and BARseq)34-38 to analyze the projections of 5,309 bulb and 30,433 piriform cortex output neurons in the mouse at single-cell resolution. We identify previously unrecognized spatial organization in connectivity along the anterior-posterior axis (A-P) of the piriform cortex. We find that both the bulb projections to the cortex and the cortical outputs are not random, but rather form gradients along the A-P axis. Strikingly, these gradients are matched: bulb neurons targeting a given location within the piriform cortex co-innervate extra-piriform regions that receive strong inputs from neurons within that piriform locus. We also identify signatures of local connectivity in the piriform cortex. Our findings suggest an organizing principle of matched direct and indirect olfactory pathways that innervate extra-piriform targets in a coordinated manner, thus supporting models of information processing that rely on structured connectivity within the olfactory system.

show abstract

Bilateral Alignment of Receptive Fields in the Olfactory Cortex

Cited by 5 publications

References 88 publications

Bilateral and unilateral odor processing and odor perception

Bilateral and unilateral odor processing and odor perception

Odor representations from the two nostrils are temporally segregated in human piriform cortex

Wiring logic of the early rodent olfactory system revealed by high-throughput sequencing of single neuron projections

Contact Info

Product

Resources

About