1
|
Liu M, Wang Y, Jiang L, Zhang X, Wang C, Zhang T. Research progress of the inferior colliculus: from Neuron, neural circuit to auditory disease. Brain Res 2024; 1828:148775. [PMID: 38244755 DOI: 10.1016/j.brainres.2024.148775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 01/10/2024] [Accepted: 01/15/2024] [Indexed: 01/22/2024]
Abstract
The auditory midbrain, also known as the inferior colliculus (IC), serves as a crucial hub in the auditory pathway. Comprising diverse cell types, the IC plays a pivotal role in various auditory functions, including sound localization, auditory plasticity, sound detection, and sound-induced behaviors. Notably, the IC is implicated in several auditory central disorders, such as tinnitus, age-related hearing loss, autism and Fragile X syndrome. Accurate classification of IC neurons is vital for comprehending both normal and dysfunctional aspects of IC function. Various parameters, including dendritic morphology, neurotransmitter synthesis, potassium currents, biomarkers, and axonal targets, have been employed to identify distinct neuron types within the IC. However, the challenge persists in effectively classifying IC neurons into functional categories due to the limited clustering capabilities of most parameters. Recent studies utilizing advanced neuroscience technologies have begun to shed light on biomarker-based approaches in the IC, providing insights into specific cellular properties and offering a potential avenue for understanding IC functions. This review focuses on recent advancements in IC research, spanning from neurons and neural circuits to aspects related to auditory diseases.
Collapse
Affiliation(s)
- Mengting Liu
- Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Yuyao Wang
- Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Li Jiang
- Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Xiaopeng Zhang
- Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Chunrui Wang
- Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Tianhong Zhang
- Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China.
| |
Collapse
|
2
|
Liu M, Gao Y, Xin F, Hu Y, Wang T, Xie F, Shao C, Li T, Wang N, Yuan K. Parvalbumin and Somatostatin: Biomarkers for Two Parallel Tectothalamic Pathways in the Auditory Midbrain. J Neurosci 2024; 44:e1655232024. [PMID: 38326037 PMCID: PMC10919325 DOI: 10.1523/jneurosci.1655-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 01/15/2024] [Accepted: 01/20/2024] [Indexed: 02/09/2024] Open
Abstract
The inferior colliculus (IC) represents a crucial relay station in the auditory pathway, located in the midbrain's tectum and primarily projecting to the thalamus. Despite the identification of distinct cell classes based on various biomarkers in the IC, their specific contributions to the organization of auditory tectothalamic pathways have remained poorly understood. In this study, we demonstrate that IC neurons expressing parvalbumin (ICPV+) or somatostatin (ICSOM+) represent two minimally overlapping cell classes throughout the three IC subdivisions in mice of both sexes. Strikingly, regardless of their location within the IC, these neurons predominantly project to the primary and secondary auditory thalamic nuclei, respectively. Cell class-specific input tracing suggested that ICPV+ neurons primarily receive auditory inputs, whereas ICSOM+ neurons receive significantly more inputs from the periaqueductal gray and the superior colliculus (SC), which are sensorimotor regions critically involved in innate behaviors. Furthermore, ICPV+ neurons exhibit significant heterogeneity in both intrinsic electrophysiological properties and presynaptic terminal size compared with ICSOM+ neurons. Notably, approximately one-quarter of ICPV+ neurons are inhibitory neurons, whereas all ICSOM+ neurons are excitatory neurons. Collectively, our findings suggest that parvalbumin and somatostatin expression in the IC can serve as biomarkers for two functionally distinct, parallel tectothalamic pathways. This discovery suggests an alternative way to define tectothalamic pathways and highlights the potential usefulness of Cre mice in understanding the multifaceted roles of the IC at the circuit level.
Collapse
Affiliation(s)
- Mengting Liu
- Department of Otorhinolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Yixiao Gao
- Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Fengyuan Xin
- School of Biomedical Engineering, Tsinghua University, Beijing 100084, China
| | - Ying Hu
- Zhili College, Tsinghua University, Beijing 100084, China
| | - Tao Wang
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Fenghua Xie
- School of Biomedical Engineering, Tsinghua University, Beijing 100084, China
- Tsinghua Laboratory of Brain and Intelligence, Tsinghua University, Beijing 100084, China
| | - Chengjun Shao
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Tianyu Li
- School of Biomedical Engineering, Tsinghua University, Beijing 100084, China
| | - Ningyu Wang
- Department of Otorhinolaryngology Head and Neck Surgery, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China
| | - Kexin Yuan
- School of Biomedical Engineering, Tsinghua University, Beijing 100084, China
- Tsinghua Laboratory of Brain and Intelligence, Tsinghua University, Beijing 100084, China
- IDG/McGovern Institute for Brain Research at Tsinghua, Tsinghua University, Beijing 10084, China
| |
Collapse
|
3
|
Homma NY, Bajo VM. Lemniscal Corticothalamic Feedback in Auditory Scene Analysis. Front Neurosci 2021; 15:723893. [PMID: 34489635 PMCID: PMC8417129 DOI: 10.3389/fnins.2021.723893] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 07/30/2021] [Indexed: 12/15/2022] Open
Abstract
Sound information is transmitted from the ear to central auditory stations of the brain via several nuclei. In addition to these ascending pathways there exist descending projections that can influence the information processing at each of these nuclei. A major descending pathway in the auditory system is the feedback projection from layer VI of the primary auditory cortex (A1) to the ventral division of medial geniculate body (MGBv) in the thalamus. The corticothalamic axons have small glutamatergic terminals that can modulate thalamic processing and thalamocortical information transmission. Corticothalamic neurons also provide input to GABAergic neurons of the thalamic reticular nucleus (TRN) that receives collaterals from the ascending thalamic axons. The balance of corticothalamic and TRN inputs has been shown to refine frequency tuning, firing patterns, and gating of MGBv neurons. Therefore, the thalamus is not merely a relay stage in the chain of auditory nuclei but does participate in complex aspects of sound processing that include top-down modulations. In this review, we aim (i) to examine how lemniscal corticothalamic feedback modulates responses in MGBv neurons, and (ii) to explore how the feedback contributes to auditory scene analysis, particularly on frequency and harmonic perception. Finally, we will discuss potential implications of the role of corticothalamic feedback in music and speech perception, where precise spectral and temporal processing is essential.
Collapse
Affiliation(s)
- Natsumi Y. Homma
- Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, CA, United States
- Coleman Memorial Laboratory, Department of Otolaryngology – Head and Neck Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Victoria M. Bajo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
4
|
Lohse M, Dahmen JC, Bajo VM, King AJ. Subcortical circuits mediate communication between primary sensory cortical areas in mice. Nat Commun 2021; 12:3916. [PMID: 34168153 PMCID: PMC8225818 DOI: 10.1038/s41467-021-24200-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 06/02/2021] [Indexed: 12/20/2022] Open
Abstract
Integration of information across the senses is critical for perception and is a common property of neurons in the cerebral cortex, where it is thought to arise primarily from corticocortical connections. Much less is known about the role of subcortical circuits in shaping the multisensory properties of cortical neurons. We show that stimulation of the whiskers causes widespread suppression of sound-evoked activity in mouse primary auditory cortex (A1). This suppression depends on the primary somatosensory cortex (S1), and is implemented through a descending circuit that links S1, via the auditory midbrain, with thalamic neurons that project to A1. Furthermore, a direct pathway from S1 has a facilitatory effect on auditory responses in higher-order thalamic nuclei that project to other brain areas. Crossmodal corticofugal projections to the auditory midbrain and thalamus therefore play a pivotal role in integrating multisensory signals and in enabling communication between different sensory cortical areas.
Collapse
Affiliation(s)
- Michael Lohse
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK.
- Sainsbury Wellcome Centre, London, UK.
| | - Johannes C Dahmen
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Victoria M Bajo
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK
| | - Andrew J King
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK.
| |
Collapse
|
5
|
Liu Y, Zhang G, Yu H, Li H, Wei J, Xiao Z. Robust and Intensity-Dependent Synaptic Inhibition Underlies the Generation of Non-monotonic Neurons in the Mouse Inferior Colliculus. Front Cell Neurosci 2019; 13:131. [PMID: 31024260 PMCID: PMC6460966 DOI: 10.3389/fncel.2019.00131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 03/15/2019] [Indexed: 11/28/2022] Open
Abstract
Intensity and frequency are the two main properties of sound. The non-monotonic neurons in the auditory system are thought to represent sound intensity. The central nucleus of the inferior colliculus (ICC), as an important information integration nucleus of the auditory system, is also involved in the processing of intensity encoding. Although previous researchers have hinted at the importance of inhibitory effects on the formation of non-monotonic neurons, the specific underlying synaptic mechanisms in the ICC are still unclear. Therefore, we applied the in vivo whole-cell voltage-clamp technique to record the excitatory and inhibitory postsynaptic currents (EPSCs and IPSCs) in the ICC neurons, and compared the effects of excitation and inhibition on the membrane potential outputs. We found that non-monotonic neuron responses could not only be inherited from the lower nucleus but also be created in the ICC. By integrating with a relatively weak IPSC, approximately 35% of the monotonic excitatory inputs remained in the ICC. In the remaining cases, monotonic excitatory inputs were reshaped into non-monotonic outputs by the dominating inhibition at high intensity, which also enhanced the non-monotonic nature of the non-monotonic excitatory inputs.
Collapse
Affiliation(s)
- Yun Liu
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Mental Health of the Ministry of Education, Guangzhou, China
| | - Guodong Zhang
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Mental Health of the Ministry of Education, Guangzhou, China
| | - Haipeng Yu
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Mental Health of the Ministry of Education, Guangzhou, China
| | - He Li
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Mental Health of the Ministry of Education, Guangzhou, China
| | - Jinxing Wei
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Mental Health of the Ministry of Education, Guangzhou, China
| | - Zhongju Xiao
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Mental Health of the Ministry of Education, Guangzhou, China
| |
Collapse
|
6
|
Subtypes of GABAergic cells in the inferior colliculus. Hear Res 2018; 376:1-10. [PMID: 30314930 DOI: 10.1016/j.heares.2018.10.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 09/26/2018] [Accepted: 10/02/2018] [Indexed: 12/27/2022]
Abstract
The inferior colliculus occupies a central position in ascending and descending auditory pathways. A substantial proportion of its neurons are GABAergic, and these neurons contribute to intracollicular circuits as well as to extrinsic projections to numerous targets. A variety of types of evidence - morphology, physiology, molecular markers - indicate that the GABAergic cells can be divided into at least four subtypes that serve different functions. However, there has yet to emerge a unified scheme for distinguishing these subtypes. The present review discusses these criteria and, where possible, relates the different properties. In contrast to GABAergic cells in cerebral cortex, where subtypes are much more thoroughly characterized, those in the inferior colliculus contribute substantially to numerous long range extrinsic projections. At present, the best characterized subtype is a GABAergic cell with a large soma, dense perisomatic synaptic inputs and a large axon that provides rapid auditory input to the thalamus. This large GABAergic subtype projects to additional targets, and other subtypes also project to the thalamus. The eventual characterization of these subtypes can be expected to reveal multiple functions of these inhibitory cells and the many circuits to which they contribute.
Collapse
|