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Book Ch Latest Findings Tan 2012

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Book Ch Latest Findings Tan 2012
Author: Uner Tan
Publisher: Cukurova University
44 pages
One time payment: €0.00
Required subscription: Free
Type of publication: Article
ISBN/ISSN: 978-953-307-865-6
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Description:

Uner Tan syndrome (UTS), discovered in 2005 in Southern Turkey, mainly consists of

 

habitual quadrupedal locomotion, mental retardation, and dysarthric or no speech, with or

 

without cerebello-vermial hypoplasia and mildly simplified cortical gyri. A man walking on

 

all four extremities, probably exhibiting the symptoms of the UTS, was first discovered and

 

reported in 1917, nearly a hundred years ago, by a British traveler on the Middle Black Sea

 

coast, near Samsun, on the famous Baghdad road, during the time of the Ottoman Empire.

 

Between 2005 and 2010, 10 families with 33 cases—13 women (42.4%) and 19 men (57.6%)—

 

were discovered in Turkey (see Table 1). In addition, there were two male children (4 and 12

 

years old) resident in Adana and Istanbul, who were normal in cognitive abilities, with no

 

neurological signs and symptoms, and normal brain MRIs, but with facultative quadrupedal

 

locomotion. Including the cases from Brazil, Iraq, Mexico, and Chile, there were 25 men

 

(64.1%) and 14 women (35.9%) around the world. Statistics showed that the number of men

 

significantly exceeded the number of women (p<.05), suggesting a male preponderance in

 

UTS. Genealogical analysis suggested autosomal recessive transmission linked to

 

chromosome 17p13.1.13.3 with a missense mutation in the WDR81 gene in the affected

 

members of the first described Iskenderun family. Homozygocity was found in two families

 

resident in remote villages of Southern and Northern Turkey, and was mapped to a region

 

on chromosome 9p24 that included the very low density lipoprotein receptor gene, VLDLR.

 

These results suggested that UTS may be a genetically heterogeneous syndrome.

 

Interestingly, the mother of the affected siblings in the Iskenderun family had Type-I

 

diabetes, which may be associated with congenital malformations such as caudal regression

 

in mice, suggesting that the maternal diabetes in some cases with UTS could be associated

 

with neuronal damage, resulting in impaired balance.

 

UTS can be considered within the framework of the non-progressive autosomal recessive

 

cerebellar ataxias, which are associated with various genetic mutations. Among these

 

conditions, such as disequilibrium syndrome (DES), Cayman ataxia, and Joubert syndrome,

 

there are overlapping symptoms, like truncal ataxia, psychomotor delay, and dysarthric

 

speech. All of these syndromes show genetic heterogeneity, which is characteristic for many

 

diseases. Thus, genetics alone do not seem to be informative for the origins of many

 

syndromes, including UTS. From the viewpoint of dynamical systems theory, there may not

 

be a single factor including a genetic code that predetermines the emergence of human

 

quadrupedalism, seen, for instance, in UTS. Rather, it may involve a self-organization

 

 

Üner Tan Syndrome: Review and Emergence of

 

 

Human Quadrupedalism in Self-Organization, Attractors and Evolutionary Perspectives 33

 

 

 

process, consisting of many decentralized and local interactions among neuronal, genetic,

 

and environmental subsystems.

 

UTS was divided into two subgroups: Type-I and Type-II, the former exhibiting no

 

hypotonia, and the latter being associated with early hypotonia. The comparison with other

 

closely related syndromes, such as DES, Cayman ataxia, and Joubert syndrome, indicated

 

that UTS may be distinguished from these syndromes by habitual locomotion on all four

 

extremities, normal stature, and normal muscle tone in Type-I cases, but early hypotonia in

 

Type-II cases. For these reasons, UTS may be considered a distinct entity among the

 

cerebellar ataxias.

 

The most remarkable characteristic of UTS is diagonal-sequence quadrupedal locomotion,

 

similar to the non-human primates and contrary to non-primate species. The evolutionary

 

advantage of diagonal-sequence quadrupedal locomotion is not known. However,

 

interestingly, there seems to be an evolutionary advantage of this type of locomotion for

 

primate evolution, with regard to the emergence of complex neural circuits with related

 

highly complex structures. Namely, only primates with diagonal-sequence quadrupedal

 

locomotion followed an evolution favoring larger brains, highly developed cognitive

 

abilities, highly developed hand skills, and language, with erect posture and bipedal

 

locomotion, creating the unity of human beings. The non-primate mammals using lateralsequence

 

quadrupedal locomotion did not show a similar phylogenetic progress compared

 

to those with diagonal-sequence quadrupedal locomotion, which, in essence, was the

 

phylogenetically oldest type of locomotion since it was a characteristic of the first tetrapods

 

during the Devonian period. This suggests that the ancestral neural networks responsible

 

for the diagonal-sequence quadrupedal locomotion were reserved for at least nearly 400

 

million years since the Devonian tetrapod-like fishes.

 

The human quadrupedal locomotion seen in UTS showed some similarities with nonhuman

 

primates. For instance, the human quadrupeds supported their body weight more

 

on the feet than on the hands during quadrupedal locomotion, in a similar way to the

 

weight distribution during location in most non-human primates. In contrast, non-primate

 

quadrupedal mammals usually support their body weight more on the forelimbs than their

 

hind limbs. The body weight support patterns in non-human and human primates suggests

 

that the reduced body weight on hands than feet would be beneficial for the development of

 

fine hand skills in primates. The complete freeing of hands in human beings during upright

 

walking would be entirely associated with highly developed hand skills compared to the

 

non-human primates walking on all four extremities.

 

It was suggested that UTS may be considered a further example for Darwinian diseases,

 

which may be associated with an evolutionary understanding of the disorders using

 

evolutionary principles, such as natural selection. In this context, UTS may also be

 

considered a disease with phylogenetic regression. In some UTS cases, the supraorbital tori

 

were remarkably prominent, and were more or less similar to those in non-human primates.

 

This was taken to be an ancestral feature, in addition to the diagonal-sequence quadrupedal

 

locomotion, and the body weight being supported predominantly by the hind legs.

 

Human quadrupedalism was proposed to be a phenotypic example of evolution in reverse,

 

i.e., the reacquisition by derived populations of the same character states as those of ancestor

 

 

34 Latest Findings in Intellectual and Developmental Disabilities Research

 

 

 

populations. On the other hand, UTS may be considered within the framework of

 

phylogenetic diseases (phylogenetic regression), which may be related to the phenotypic

 

backward evolutionary atavism (the reappearance of a lost character (either morphological

 

or behavioral) that was typical of remote ancestors). The habitual diagonal-sequence

 

quadrupedal locomotion, standing with bent knees and bent trunk (flexor posture contrary

 

to the extensor posture in modern human beings), prominent supraorbital tori, fist walking

 

with bent fingers, and non-opposable thumb, may be related to ancestral characteristics in

 

the UTS cases. The diagonal-sequence quadrupedal locomotion (habitual or facultative) was

 

also the preferred gait of some individuals with entirely normal brains, probably as a result

 

of the neural networks preserved during nearly 400 million years of evolution.

 

The emergence of human quadrupedalism was related to the self-organizing processes

 

occurring in complex systems, which selects or attracts one preferred behavioral state or

 

locomotor trait out of many possible attractor states. Since this is a spontaneous and

 

unpredictable event, behavioral variability being a common precursor, the dynamic

 

systems provide enormous flexibilities. According to the interactions of the internal

 

components with their sensitivities to external conditions, the complex dynamical systems

 

prefer a behavioral mode or modes. Concerning the locomotor patterns, the dynamical

 

systems (brain and body) of the developing child may prefer or create some kind of

 

locomotion, according to interactions of the internal components and environmental

 

conditions, without a direct role of any causative factor(s), such as genetic or neural codes.

 

This self-organization occurs through the interactions of its components, endogenously

 

(within the brain), and/or exogenously through some environmental influence, but

 

without any external force.

 

The emergence of human locomotion is a developmental event in which the selforganization

 

processes play the major role, suggesting no innate or previously prescribed

 

codes are essential for the emergence of walking during locomotor development. The

 

developing skeleto-motor system of the individuals with impaired balance may selforganize,

 

which is itself triggered by the exogenous environmental constraints, and they will

 

then find the most suitable and most comfortable, and hence preferred, mode of locomotion,

 

spontaneously generating novel and organized forms and attractor states. In UTS, these

 

spontaneous, unpredictable strange attractors may include diagonal-sequence quadrupedal

 

locomotion, as also seen in the non-human primates, or an entirely unpredictable novel

 

quadrupedal locomotion may emerge, such as the inverse (face-up) quadrupedal

 

locomotion. More examples of the unpredictable, self-organized, and emergent strange

 

attractors were presented in this article. The contribution of the single factors such as the

 

genetic and/or neural codes (central pattern generators) to the emergence of the locomotor

 

patterns during locomotor development were rejected, considering the current scientific

 

research in these fields, consistent with the concept of self-organization, suggesting no

 

single element has causal priority.

 

 

About the publisher:

 

CURRICULUM VITAE

 

 

 

 

 

PROF. DR. UNER TAN

 

Honorary Member of the Turkish Academy of Sciences

 

Professional Member of the American Academy of Neuropsychology

 

Liaison Member of the American Psychological Association

 

Member of the World Innovation Foundation

 

Senior Researcher in Cukurova University

 

 

 

 

 

PERSONAL INFORMATION 

 

Place of birth: Unye, Ordu, Turkey

 

Date of birth : 1 May 1937

 

 

 

EDUCATION

 

 

 

1945-1950: Primary School, Vezirkopru, Samsun, Turkey

 

1950-1954: Middle School and Lyceum, Osmancik and Corum, Turkey

 

1954-1956: Lyceum, Izmir, Turkey

 

1956-1960: Egean University, Medical School, Izmir, Turkey

 

1960-1966: Goettingen University, Medical School, Germany

 

1960-1966: Ph.D. Max-Planck Institute for Medical Research, Goettingen, Germany

 

 

 

ACADEMIC ACTIVITIES

 

 

 

1966-1967:Ass. Prof., Max-Planck Institute for Medical Reserach, Goettingen, Germany

 

1967-1969: Ass. Prof. Institute of Physiology, Goettingen University, Germany

 

1969-1973: Lecturer, Institute of Physiology, Hacettepe University, Ankara, Turkey

 

1973-1977: Assoc. Professor for Physiology, Medical Schools of Hacettepe (Ankara) and

 

     Ataturk (Erzurum) Universities, Turkey

 

1977-1999: Professor of Physiology, Ataturk University, Medical School, Erzurum,Turkey

 

1973-1999: Head of the Department of Physiology, Ataturk University, Erzurum, Turkey

 

1999-2002: Head of the Department of Physiology, Medical School, BlackSea Technical

 

     University, Trabzon, Turkey

 

2002-2004: Head of the Department of Neurophysiology Unit, Adana, Turkey

 

 

 

EDITORIAL ACTIVITIES

 

 

 

2002-2009:  Editor, International Journal of Neuroscience, USA

 

2002-2008: Editorial board, Perceptual and Motor Skills, USA

 

2002-present: Editor for Neurophysiology section in the Journal of Neuroquantology, Turkey

 

2008-present: Editorial Board in the Journal of Neuroquantology, Izmir, Turkey

 

2011: Editorial Board in “International Journal of Basic and Clinical Research” 

 

1980-present: Reviewer for the various international and national scientific periodicals

 

 

 

 

 

AWARDS

 

 

 

1973: Science Award for young scientists, Turkish Scientific and Technical Council

 

1986: Science Award, Turkish Scientific and Technical Council, Ankara, Turkey

 

1975: Eczacibasi Medical Award, Istanbul, Turkey, Istanbul, Turkey

 

1980: Dorothea Morton First Prize for Neurological Sciences, Istanbul, Turkey

 

1988: Sedat Simavi Medical Award, Istanbul, Turkey

 

1985: Ph. D., Honoris Causa in education, USA  

 

1986: Einstein Medals for science and peace, USA

 

1987: Medal of Honour, USA

 

1991: Nobel Medals for Science and Peace, Albert Einstein Foundation, USA

 

1992: Golden Academy Award for Lifelong Achievement, USA

 

1998: Gold Record for Brain Research, American Biographical Institute, USA

 

 

 

PROFESSIONAL SOCIETIES

 

 

 

Turkish Academy of Sciences

 

American National Academy of Neuropsychology

 

New York Academy of Sciences

 

International Brain Research Organization

 

European Neuroscience Association

 

Society for Psychophysiological Research

 

National Societies for EEG, EMG, and Neurology

 

American Psychological Association

 

World Innovation Foundation

 

 

 

SCIENTIFIC STUDIES

 

 

 

Physiology and pharmacology of the spinal and cerebral motor systems

 

Epilepsy

 

Mechanisms of the effects of the antidepressant drugs

 

Microelectrode studies of the pyramidal neurons in cats

 

Asymmetric brain in mice, rats, cats, and humans

 

Primitive reflexes in human neonates

 

Sex differences in cerebral lateralization and cognition

 

Hand preference and hand skill in relation to sex hormones

 

Intelligence

 

Finger-length patterns and sex differences to sex hormones

 

Uner Tan Syndrome (habitual quadrupedalism + impaired cognition + cerebellovermial hypoplasia

 

 

 

PUBLICATIONS

 

 

 

Around 180 articles on spinocerebral motor control, intelligence, spinal and cerebral lateralization, sex differences in cognition and handedness in relation to sex hormones in men and women, finger-length patterns in relation to sex hormones, and Uner Tan Syndrome, published in periodicals included in Science Citation Index (1966-present), with nearly 2000 citations since 1966

 

 

 

 

 

 

 

FAMILIES

 

 

 

Married four times with Nazife, Sezer, Sule, and Meliha

 

Four children:

 

Alper (35ya), Utkan (30ya) from Nazife and

 

Sevgi (14ya) and Sezgi (11ya) from Meliha

 

 

 

 

 

HOBIES AND INTERESTS

 

 

 

Violin playing since 1952, first violinist in Izmir Philharmony orchestra (1956-1960) and in  

 

      the Academic Orchestra of Goettingen University, Germany  (1960-1966).

 

Stamp collecting

 

Human and animal behavior

 

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