Ultrastructural changes in primary endings of deaf white cats☆, ☆☆, ★Second Place—Resident Basic Science Award 1996

Abstract

Changes in brain structure occur as a consequence of altered experience. During maturation of the auditory nervous system, sensory deprivation is known to cause cell loss, abnormal axonal projections, and synaptic alterations. These animal data may be relevant to clinical observations that cochlear implants provide superior benefit for individuals who become deaf postlingually compared with those who become deaf prelingually. That is, implantation appears most efficacious if it occurs after functional connections are established but before deprivation-induced changes in the central auditory system. After this period, synaptic reorganization may underlie the diminished effectiveness of cochlear implants.

Deafness‐related plasticity in the inferior colliculus: gene expression profiling following removal of peripheral activity

“…Deafness (full or partial) and noise over-stimulation have been shown to lead to plastic changes in the mature central auditory pathways (Syka 2002;Moller 2005). Changes that have been reported following deafness include changes in the tonotopic map (Robertson et al 1989;Rajan et al 1993), in cell size (Sie and Rubel 1992;Dodson et al 1994;Lustig et al 1994;Lesperance et al 1995;Willott and Bross 1996;Moore et al 1997;Niparko and Finger 1997;Araki et al 1998;Edmonds et al 1999;Niparko 1999;Nishiyama et al 2000), changes in synaptic contacts and synapse morphology (Kazee et al 1995;Huchton et al 1997;Ryugo et al 1997;Niparko 1999;Russell and Moore 2002;Lee et al 2003), in neurotransmitters and receptors as well as their release, uptake and binding (Caspary et al 1995;Milbrandt et al 2000;Potashner et al 2000;Vale and Sanes 2002), in ion channels (Storey et al 2002;Mhatre et al 2004), in transcription factors (Illing et al 1999;Illing and Michler 2001;von Hehn et al 2004), in oxygen reactive species (Ohlemiller and Dugan 1999;Shi et al 2002), and in stress response molecules (Myers et al 1992;Billings et al 1995;Verstreken et al 1996;Oh et al 2000;Van Campen et al 2002;…”