Seasonal changes in the nucleoli of Purkinje cells of the hedgehog cerebellum

Giacometti, Silvia; Scherini, Elda; Bernocchi, Graziella

doi:10.1016/0006-8993(89)90732-4

Cited by 12 publications

(6 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For instance, Purkinje cell nucleoli of the cerebellum are smaller in hibernating hedgehogs compared to euthermic hedgehogs (Giacometti et al, 1989). Cone cells in the retina of hibernating 13-lined ground squirrels undergo many changes including reduction in the diameters of the membranous discs as well as the size and number of mitochondria (Reme and Young, 1977).…”

Section: Discussionmentioning

confidence: 99%

Distribution of NMDA receptor subunit NR1 in Arctic ground squirrel central nervous system

Zhao

Christian

Castillo

et al. 2006

Journal of Chemical Neuroanatomy

View full text Add to dashboard Cite

Hibernation is a natural model of neuroprotection and adult synaptic plasticity. NMDA receptors (NMDAR), which play key roles in excitotoxicity and synaptic plasticity, have not been characterized in a hibernating species. Tolerance to excitotoxicity and cognitive enhancement in Arctic ground squirrels (AGS, Spermophilus parryii) suggests that NMDAR expression may decrease in hibernation and increase upon arousal. NMDAR consist of at least one NMDAR1 (NR1) subunit, which is required for receptor function. Localization of NR1 reflects localization of the majority, if not all, NMDAR complexes. The purpose of this study, therefore, was to characterize the distribution of NR1 subunits in AGS central nervous system using immunohistochemistry. In addition, we compare NR1 expression in hippocampus of hibernating AGS (hAGS) and inter-bout euthermic AGS (ibeAGS) and assess changes in cell somata size using NR1 stained sections in three hippocampal sub-regions (CA1, CA3, and dentate gyrus). For the first time, we report that immunoreactivity of anti-NR1 is widely distributed throughout the central nervous system in AGS and is similar to other species. No differences exist in the expression and distribution of NR1 in hAGS and ibeAGS. However, we report a significant decrease in size of hippocampal CA1 and dentate gyrus NR1-expressing neuronal somata during hibernation torpor.

show abstract

Section: Discussionmentioning

confidence: 99%

Distribution of NMDA receptor subunit NR1 in Arctic ground squirrel central nervous system

Zhao

Christian

Castillo

et al. 2006

Journal of Chemical Neuroanatomy

View full text Add to dashboard Cite

show abstract

“…The nucleolus of these neurons matures progressively from a small, densely compact structure to a large one having a distinctly reticulated organization early in development. Changes in nucleolar size have also been reported to be present in Purkinje cells of the hedgehog cerebellum (Giacometti et al, 1989). In this system, nucleoli are much smaller in size during hibernation than during activity.…”

Section: Developmental Changes In Nucleoli Are Onlymentioning

confidence: 96%

Lateral magnocellular nucleus of the anterior neostriatum (LMAN) in the zebra finch: Neuronal connectivity and the emergence of sex differences in cell morphology

Nixdorf-Bergweiler

2001

Microscopy Res & Technique

View full text Add to dashboard Cite

The song system of birds provides a model system to study basic mechanisms of neuronal plasticity and development underlying learned behavior. Song learning and production involve discrete sets of interconnected nuclei in the avian brain. One of these nuclei, the lateral magnocellular nucleus of the anterior neostriatum (LMAN), is the output of the so-called anterior forebrain pathway known to be essential for learning and maintenance of song, both processes depending on auditory feedback. In zebra finches, only males sing and this sexually dimorphic behavior is mirrored by sexual dimorphism in neuronal structure that develops during ontogeny. Female zebra finches are not able to sing and nuclei of the song system are strongly reduced in size or even lacking, when compared to male brains. Only LMAN can be delineated as easily in females as in males. Since female zebra finches, despite being unable to sing, recognize song just as males do and form a memory for song (model acquisition) early in life, LMAN is a putative candidate for song acquisition in both sexes. Therefore, development of LMAN was studied at the cellular and ultrastructural level in both male and female zebra finches. Regressive development of dendritic spines, enlargement of neuronal cell body and nuclei size, as well as changes at the nucleolar level are events all occurring exclusively in males, when song learning progresses. The decline in synapse number and the augmentation in synaptic contact length at synapses in LMAN in males are indicative for synaptic plasticity, whereas in females synapse number and synaptic contact length remain unchanged.

show abstract

“…Further, the CB decrease can be related to the enhancement of the ionotropic receptor of glutamate, GluR2-3; this finding may represent a compensatory mechanism against calcium accumulation in the cells (Choi & Hartley 1993). Moreover, based on pNF-H and MAP2 data, we proved that cytoskeletal regulation and reorganisation occur, probably as a strategy to adapt neuronal functional activity to a lower CNS metabolic activity in torpid-hibernating animals (Bernocchi et al 1986;Giacometti et al 1989).…”

Section: Discussionmentioning

confidence: 70%

“…These characteristics suggest the involvement of the cerebellum in the torpor phase compared to the activity period, even though only a few studies have demonstrated overt metabolic changes in the cerebellar cortex of a deep-hibernator mammal, during hibernation (Bernocchi et al 1986;Giacometti et al 1989). …”

Section: Introductionmentioning

confidence: 99%

Changes in the cerebellar cytoarchitecture of hibernating hedgehogErinaceus europaeusL. (Mammalia): an immunocytochemical approach

Roda

Bottone

Insolia

et al. 2017

The European Zoological Journal

View full text Add to dashboard Cite

Hibernation is an amazing animal strategy to survive when the environmental temperature is very low and food resources are scarce. Successful hibernation requires a variety of complex biological adaptations, in which the brain plays a central regulatory role. Currently, little information is available regarding the morphology and functional activity of specific neurons within the cerebellar cytoarchitecture of hibernating animals. In the present study, we investigated the immunohistochemical expression of essential proteins in the cerebellum of a mammalian hibernator (i.e. hedgehog Erinaceus europaeus L.), focusing on (i) Purkinje neurons, the sole output cells of the cerebellar cortex; (ii) selected neurotransmitters involved in hibernation processes; (iii) intracellular calcium homeostasis, considering that calcium is also an important regulator of neurotransmission mechanisms; and (iv) cytoskeletal proteins, involved in maintenance of neuronal shape and axon calibre. Specifically, we studied in situ immunocytochemical changes during the torpor state of hibernation (November-March) versus the activity phase (AprilSeptember). We employed different selected markers, i.e. glutamic acid decarboxylase (GAD67) and postsynaptic glutamate ionotropic receptor GluR2-3, different calcium-binding proteins (i.e. calbindin, parvalbumin and calretinin) and cytoskeletal components (i.e. pNF-H and MAP2). In summary, our data in hibernating animals demonstrated: (i) downregulation of GAD67, indicating loss/changes of synaptic contacts on Purkinje somata and dendrites; (ii) GluR2-3 upregulation in Purkinje neurons, with a drastic decrease of calbindin expression; and (iii) decrease of normal mechanisms regulating intracellular calcium homeostasis. We also found a decrease/modification in the distribution of cytoskeletal proteins, particularly evident for pNF-H. Changes in the functional activity of Purkinje cells were accompanied by some morphological dendrite alterations, signs of degeneration in cell somata and flattened basket pinceaux at the Purkinje axon hillock. These findings confirm that hibernation makes heterothermic animals a valuable model to study physiological adaptations to adverse conditions, and also for understanding cellular and molecular mechanisms aimed at preserving mammalian organs from full degeneration and death.

show abstract

Seasonal changes in the nucleoli of Purkinje cells of the hedgehog cerebellum

Cited by 12 publications

References 8 publications

Distribution of NMDA receptor subunit NR1 in Arctic ground squirrel central nervous system

Distribution of NMDA receptor subunit NR1 in Arctic ground squirrel central nervous system

Lateral magnocellular nucleus of the anterior neostriatum (LMAN) in the zebra finch: Neuronal connectivity and the emergence of sex differences in cell morphology

Changes in the cerebellar cytoarchitecture of hibernating hedgehogErinaceus europaeusL. (Mammalia): an immunocytochemical approach

Contact Info

Product

Resources

About