**Acknowledgements**

*Prions - Some Physiological and Pathophysiological Aspects*

mational restriction to characterize different strains.

**4.3 Distribution of density variants**

density PrP oligomeric species [92].

**5. Conclusions and future outlook**

classical BSEs [85].

proves to be a highly specific and sensitive method and has been utilized to establish strain differences of typical and atypical prionopathies, e.g., the L-type BSE and

A recent report showed oligo-/poly-thiophene derivate as a potent fluorescent approach to discriminate between prion strains [86]. The excitation/emission spectra were obtained from the CWD and scrapie strains, and the interactive association between thiophene and different aggregates were used in combination with confor-

Prion strain polymerization is a sequential process where single molecules are converted to polymers via a multitude of conformational variants. Different prion strains have been identified in animal and human cases based upon differential population densities of these quaternary structures [87]. Quaternary structure conformers of PrP have been isolated and studied using sucrose density gradient by many groups [88–91]. Differential prion strains have been also identified for the rapidly progressive forms of Alzheimer's disease with distinct population of high-

Prion strains and the interspecies barriers are still enigmatic phenomena. One of the surprising things about prion protein is that this single protein can fold up in

**64**

**Figure 1.**

*stages of the diseases, and host range.*

*Prion strain emergence and interspecies transmission. The original prion strains were named as Kuru in human, BSE in cows, TSE in goat and sheep, and TME in minks. PMCA and RT-QuiC mobilized the prion strain characterization. The interspecies transmission of prions linked with host PrP oligomerization role, appearance of subassemblies named as quasispecies, tissue tropism, incubation period of prions, symptomatic* 

The study was performed within the recently established Clinical Dementia Center at the University Medical Hospital Goettingen and was partly supported by grants from the EU Joint Program Neurodegenerative Disease Research (JPND ± DEMTEST) (Biomarker-based diagnosis of rapid progressive dementias-optimization of diagnostic protocols, 01ED1201A). This work was supported by a grant from Helmholtz-Alberta Initiative-Infectious Diseases Research (HAI-IDR) and APRI-Human prions distinguishing sporadic from familial forms via structure and function as well as from the DZNE clinical project (Helmholtz).

### **Conflict of interest**

We have no conflict of interest to declare.

## **Author details**

Saima Zafar1,2\*, Neelam Younas1,2, Mohsin Shafiq1,2 and Inga Zerr1,2\*

1 Department of Neurology, Clinical Dementia Center, University Medical Center Goettingen (UMG), Georg-August University, Goettingen, Germany

2 German Center for Neurodegenerative Diseases (DZNE), Goettingen, Germany

\*Address all correspondence to: sz\_awaan@yahoo.com and ingazerr@med.uni-goettingen.de

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
