Quantitative study of cellular and volumetric growth of magnocellular and laminar auditory nuclei in developing chick brainstem

Wadhwa, Shashi; Roy, Ajitesh; Anand, Phalguni

doi:10.1007/bf02703187

Cited by 12 publications

(14 citation statements)

References 15 publications

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“…The shift from nuclear to cytoplasmic localization indicates the expression of an active form of protein in the early embryonic period and a latent form subsequently, as indicated in several studies that have demonstrated the association of c-Jun expression with developmental and experimentally induced neuronal cell death (Watson et al, 1998;Ayala et al, 1999;Oo et al, 1999). In the present study, because peak c-Jun expression and its nuclear localization as well as p-c-Jun expression coincide with the period of maximum cell loss reported earlier in these nuclei (Rubel et al, 1976;Wadhwa et al, 1997), it might be related to developmental cell death. Studies (Ayala et al, 1999) on c-Jun expression using c-Jun (SC-45) antibody (Santa Cruz Biotechnology, Inc.) reported detection of apoptosis-specific proteins (45 and 66 kDa) along with c-Jun (39kDa).…”

Section: C-fos and C-jun Are Differentially Localized During Developmentsupporting

confidence: 60%

“…Leah et al (1991) showed that the Jun immunoreactivity induced by nerve transection disappeared after nerve regeneration of the axotomized neurons. Some p-c-Jun positive pyknotic bodies found at E16 may be dying glial cells because in our earlier study (Wadhwa et al, 1997) we found peak glial cell loss at this age. In a developmental model of induced apoptotic death in substantia nigra (Oo et al, 1999) and in cultured cerebellar granule neurons (Watson et al, 1998) the number of p-c-Jun positive neurons exceeded the number expected to die.…”

Section: C-fos and C-jun Are Differentially Localized During Developmentmentioning

confidence: 86%

“…Additionally, the chick cochlear hair cells undergo cytological differentiation by E8 -10, middle ear apparatus is well formed by E10 (Whitehead and Morest, 1985a,b), and auditory nuclei show maximal embryonic cell death between E10 -13 (Rubel et al, 1976;Wadhwa et al, 1997). In a recent study (Sato and MomoseSato, 2003) optically recorded spike action potential to cochlear nerve stimulation at E7 as well as postsynaptic activity related to N-methyl-D-aspartate receptors at E6 were demonstrated in the chick auditory nuclei, indicating that development of sensory information transfer in the auditory pathway is much earlier.…”

Section: Sound Stimuli and Grouping Of Animalsmentioning

confidence: 99%

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Developmentally regulated expression of c‐Fos and c‐Jun in the brainstem auditory nuclei of Gallus domesticus is modified by prenatal auditory enrichment

et al. 2004

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Recognition of mother's voice by human neonates and behavioral responses of birds and animals to sounds experienced prenatally emphasize the role of sensory inputs in auditory system development. Spontaneous and experience driven neural activity influence the neural circuits' refinement in developing brain. However, cellular mechanisms endowing plasticity for such structural refinement during critical developmental periods are less understood. Sensory stimulation induces fluctuating expression of transcription factors (TFs) of Fos, Jun, and Krox families in the related brain nuclei to activate genes to synthesize proteins such as those needed for cytoskeletal structures, ion channels, and regeneration. To understand the cellular mechanism of response to prenatal auditory stimulation, we studied the expression of c-Fos and c-Jun in brainstem auditory nuclei, nucleus magnocellularis, and nucleus laminaris of the domestic chick. The chick brainstems, five each of E8 (embryonic day 8), E12, E16, E20, and posthatch day 1 were processed for immunohistochemistry as well as Western blotting and quantified using image analysis systems. In controls, c-Fos and c-Jun expression in both the nuclei was developmentally up-regulated. Reduced c-Fos expression and increase in c-Jun was temporarily observed between E12-16. In the stimulated groups, c-Fos expression was elevated while c-Jun showed a reduction matched to controls. This diametrically opposing pattern of c-Fos and c-Jun expression in response to stimulation is indicative of cell survival. Thus the expression of TFs in the auditory nuclei shows a relationship beyond a simple stimulation-activity-expression. While developmental signals control the expression of TFs, extra sensory stimulation modulates their expression to possibly support neuronal survival and enhance synthesis of other proteins.

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Section: C-fos and C-jun Are Differentially Localized During Developmentsupporting

confidence: 60%

Section: C-fos and C-jun Are Differentially Localized During Developmentmentioning

confidence: 86%

Section: Sound Stimuli and Grouping Of Animalsmentioning

confidence: 99%

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Developmentally regulated expression of c‐Fos and c‐Jun in the brainstem auditory nuclei of Gallus domesticus is modified by prenatal auditory enrichment

et al. 2004

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“…This is in contrast to what has been reported in chickens, where NL shows a 19% reduction in the final number of cells, whereas NM shows no significant cell death [Rubel et al, 1976;Parks, 1979;Solum et al, 1997]. A more recent report using stereological counting methods to examine cell death in the chicken has found 43% cell death in NM and 52% cell death in NL [Wadhwa et al, 1997]. The discrepancies in the extent of cell death with previously reported data may reside in differences in the strains of chickens, or in the methods used.…”

Section: Mechanisms That Underlie Hyperplasia: Cell Birth and Cell Deathcontrasting

confidence: 54%

“…These two species show marked differences in the relative size of their auditory nuclei, and have been models for the study of auditory function Rubel and Fritzsch, 2002]. Cell death and cell birth have been previously described in the chicken [Rubel et al, 1976;Parks, 1979;Solum et al, 1997;Wadhwa et al, 1997]. We used timed single injections of 3 H-thymidine in barn owl embryos to determine when the progenitor cells of NA, NM and NL underwent their final mitotic division ( fig.…”

Section: Mechanisms That Underlie Hyperplasia: Cell Birth and Cell Deathmentioning

confidence: 99%

Bigger Brains or Bigger Nuclei? Regulating the Size of Auditory Structures in Birds

2004

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Increases in the size of the neuronal structures that mediate specific behaviors are believed to be related to enhanced computational performance. It is not clear, however, what developmental and evolutionary mechanisms mediate these changes, nor whether an increase in the size of a given neuronal population is a general mechanism to achieve enhanced computational ability. We addressed the issue of size by analyzing the variation in the relative number of cells of auditory structures in auditory specialists and generalists. We show that bird species with different auditory specializations exhibit variation in the relative size of their hindbrain auditory nuclei. In the barn owl, an auditory specialist, the hindbrain auditory nuclei involved in the computation of sound location show hyperplasia. This hyperplasia was also found in songbirds, but not in non-auditory specialists. The hyperplasia of auditory nuclei was also not seen in birds with large body weight suggesting that the total number of cells is selected for in auditory specialists. In barn owls, differences observed in the relative size of the auditory nuclei might be attributed to modifications in neurogenesis and cell death. Thus, hyperplasia of circuits used for auditory computation accompanies auditory specialization in different orders of birds.

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Effect of prenatal auditory stimulation on numerical synaptic density and mean synaptic height in the posthatch Day 1 chick hippocampus

Chaudhury

Nag

Wadhwa

2008

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Previous studies on prenatal auditory stimulation by species-specific sound or sitar music showed enhanced morphological and biochemical changes in chick hippocampus, which plays an important role in learning and memory. Changes in the efficiency of synapses, synaptic morphology and de novo synapse formation affects learning and memory. Therefore, in the present study, we set out to investigate the mean synaptic density and mean synaptic height at posthatch Day 1 in dorsal and ventral part of chick hippocampus following prenatal auditory stimulation. Fertilized 0 day eggs of domestic chick incubated under normal conditions were exposed to patterned sounds of species-specific and sitar music at 65 dB levels for 15 min/h round the clock (frequency range: 100-6300 Hz) from embryonic Day 10 till hatching. The synapses identified under transmission electron microscope were estimated for their numerical density by physical disector method and also the mean synaptic height calculated. Our results demonstrate a significant increase in mean synaptic density with no alterations in the mean synaptic height following both types of auditory stimulation in the dorsal as well as ventral part of the hippocampus. The observed increase in mean synaptic density suggests enhanced synaptic substrate to strengthen hippocampal function.

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Quantitative study of cellular and volumetric growth of magnocellular and laminar auditory nuclei in developing chick brainstem

Cited by 12 publications

References 15 publications

Developmentally regulated expression of c‐Fos and c‐Jun in the brainstem auditory nuclei of Gallus domesticus is modified by prenatal auditory enrichment

Developmentally regulated expression of c‐Fos and c‐Jun in the brainstem auditory nuclei of Gallus domesticus is modified by prenatal auditory enrichment

Bigger Brains or Bigger Nuclei? Regulating the Size of Auditory Structures in Birds

Effect of prenatal auditory stimulation on numerical synaptic density and mean synaptic height in the posthatch Day 1 chick hippocampus

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