The structure of neurons in the central auditory system is vulnerable to various kinds of acoustic exposures during the critical postnatal developmental period. Here we explored long-term effects of exposure to an acoustically enriched environment (AEE) during the third and fourth weeks of the postnatal period in rat pups. AEE consisted of a spectrally and temporally modulated sound of moderate intensity, reinforced by a behavioral paradigm. At the age of 3-6 months, a Golgi-Cox staining was used to evaluate the morphology of neurons in the inferior colliculus (IC), the medial geniculate body (MGB), and the auditory cortex (AC). Compared to controls, rats exposed to AEE showed an increased mean dendritic length and volume and the soma surface in the external cortex and the central nucleus of the IC. The spine density increased in both the ventral and dorsal divisions of the MGB. In the AC, the total length and volume of the basal dendritic segments of pyramidal neurons and the number and density of spines on these dendrites increased significantly. No differences were found on apical dendrites. We also found an elevated number of spines and spine density in non-pyramidal neurons. These results show that exposure to AEE during the critical developmental period can induce permanent changes in the structure of neurons in the central auditory system. These changes represent morphological correlates of the functional plasticity, such as an improvement in frequency tuning and synchronization with temporal parameters of acoustical stimuli.

• MeSH
• akustická stimulace MeSH
• colliculus inferior cytologie   fyziologie   MeSH
• dendritické trny fyziologie   MeSH
• dendrity fyziologie   MeSH
• krysa rodu rattus MeSH
• metathalamus cytologie   fyziologie   MeSH
• neurony cytologie   fyziologie   MeSH
• neuroplasticita fyziologie   MeSH
• novorozená zvířata MeSH
• potkani Long-Evans MeSH
• sluchová dráha cytologie   fyziologie   MeSH
• sluchové korové centrum cytologie   fyziologie   MeSH
• tvar buňky fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The properties of glycine receptors (GlyRs) depend upon their subunit composition. While the prevalent adult forms of GlyRs are heteromers, previous reports suggested functional α homomeric receptors in mature nervous tissues. Here we show two functionally different GlyRs populations in the rat medial nucleus of trapezoid body (MNTB). Postsynaptic receptors formed α1/β-containing clusters on somatodendritic domains of MNTB principal neurons, colocalizing with glycinergic nerve endings to mediate fast, phasic IPSCs. In contrast, presynaptic receptors on glutamatergic calyx of Held terminals were composed of dispersed, homomeric α1 receptors. Interestingly, the parent cell bodies of the calyces of Held, the globular bushy cells of the cochlear nucleus, expressed somatodendritic receptors (α1/β heteromers) and showed similar clustering and pharmacological profile as GlyRs on MNTB principal cells. These results suggest that specific targeting of GlyR β-subunit produces segregation of GlyR subtypes involved in two different mechanisms of modulation of synaptic strength.

• MeSH
• dendritické trny fyziologie   MeSH
• elektrická stimulace MeSH
• elektrofyziologické jevy MeSH
• excitační postsynaptické potenciály účinky léků   MeSH
• glycin fyziologie   MeSH
• glycinové látky farmakologie   MeSH
• imunoelektronová mikroskopie MeSH
• imunohistochemie MeSH
• kinetika MeSH
• krysa rodu rattus MeSH
• metoda terčíkového zámku MeSH
• nervová zakončení metabolismus   MeSH
• potkani Wistar MeSH
• receptory glycinu účinky léků   metabolismus   MeSH
• receptory presynaptické metabolismus   MeSH
• sluchová dráha metabolismus   MeSH
• synapse metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH