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Louis Barkhouse Flexner Papers


Held at: University of Pennsylvania: University Archives and Records Center [Contact Us]3401 Market Street, Suite 210, Philadelphia, Pennsylvania 19104

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Louis Barkhouse Flexner was a Professor of Anatomy and Chair of the Anatomy Department at the University of Pennsylvania's School of Medicine from 1951 to 1967, a founder of the University of Pennsylvania's Institute of Neurological Sciences (now called the Mahoney Institute for Neurosciences), and medical researcher noted for his work pertaining to the biochemistry of memory.

Flexner was born on January 7, 1902 in Louisville, Kentucky to Washington Flexner and Ida Barkhouse Flexner. Louis was born into a family noted for its contributions to the medical field – his uncle Simon Flexner (1863-1946) was a Professor of Pathology at the University of Pennsylvania's School of Medicine from 1899 to 1903 and later served as Director of the Rockefeller Center for Medical Research in New York City; another uncle, Abraham Flexner (1866-1959), organized the Institute for Advanced Study in Princeton, New Jersey, and wrote Medical Education in the United States and Canada in 1910, which was considered the definitive study of North American medical education at the time. Perhaps already following in the footsteps of his uncles, at age seven Louis won a Louisville newspaper's writing contest on "How I Intend to Earn My Living" in which he explained his intention to one day cure epilepsy.

After earning a B.S. from the University of Chicago in 1923, Flexner received his medical education at Johns Hopkins University School of Medicine where he was mentored by Dr. Lewis H. Weed, Dean of the School of Medicine. After earning an M.D. in 1927, Flexner worked for two years under Dr. Leonor Michaelis, a famous biochemist who was then on the faculty of Johns Hopkins. In 1929 Flexner turned down an opportunity to spend a year in Vienna, Austria working with Sigmund Freud in order to take an internship at the University of Chicago Clinics. After eight months of clinic work, Flexner returned to the John Hopkins Anatomy Department where he would remain until 1939.

It was at Johns Hopkins where Flexner met his wife, Josefa Barba-Gose. A native of Barcelona, Spain, she was educated at the Universities of Barcelona and Madrid and earned a doctorate in pharmacy in 1927. She had been awarded a scholarship to work as a research associate at Johns Hopkins when she and Flexner met in the early 1930s. They were married in 1938. Louis and Josefa were not only spouses but also colleagues and partners in scientific research, conducting experiments and co-authoring numerous articles together for many decades.

Flexner was offered a position in the Department of Embryology at the Carnegie Institution in Washington (now called the Carnegie Institution for Science) in 1941 where his research on the biochemistry of development gained widespread attention. During World War II he remained at Carnegie and simultaneously served as Technical Aide to the Committee on Aviation Medicine of the National Research Council-Committee on Medical Research, which studied the safety and effectiveness of aviators operating under the rapidly changing conditions of aerial warfare.

In 1951 Flexner moved to Philadelphia after he accepted a position as a Professor of Anatomy and Chair of the Anatomy Department at the University of Pennsylvania. He developed the anatomy department based on three disciplines of medical research which he felt were soon to become prominent and were "appropriate" for an anatomy department: cell differentiation and development, ultrastructure and imaging, and neuroscience. Flexner felt that neuroscience especially needed to be multidisciplinary to succeed. At the time the study of the brain sciences was spread across many fields (anatomy, biology, psychiatry and psychology to name a few) and functioned relatively independent of each other. Flexner believed that collaboration amongst all neuroscientists and integration of research would benefit the field greatly. To that end he spearheaded the organization of the University of Pennsylvania's Institute of Neurological Sciences in 1953. Now called the Mahoney Institute for Neurosciences, it is nationally recognized as having been a leader in the growth of neuroscience.

Flexner was a member the American Academy of Arts and Sciences, the American Association of Anatomists, the American Philosophical Society, and the National Academy of Sciences. He was on the boards of the National Council to Combat Blindness, the National Paraplegic Society, the National Research Council, the United Cerebral Palsy Association, and the United States Public Health Service.

Flexner "retired" in 1967 though he continued to conduct research and instruct medical students into his nineties. He died on March 29, 1996, aged 94, survived by his wife, Josefa, and his sister, Miriam Maderer.

The Louis Barkhouse Flexner papers mostly consist of offprints from scholarly journals of articles Flexner authored or co-authored. These offprints date from early in Flexner's professional life in the 1920s through to the 1980s. The General File series contains curricula vitae for both Flexner and his wife and partner in research, Josefa, as well as handwritten drafts of talks Flexner gave at various events, a small collection of photographs, and offprints inscribed by his uncles, Abraham and Simon Flexner, who both made significant contributions to the field of medicine. Lastly, there is correspondence that is of a mixed professional and personal nature.

The papers of Louis Barkhouse Flexner are organized into three series – General File, Correspondence and Writings – which are each arranged alphabetically.

The Louis Barkhouse Flexner papers were donated to the University Archives (UARC) by Doerte R. Smith in 2001 (accession number 2001:033).

University of Pennsylvania: University Archives and Records Center
Finding Aid Author
Timothy H. Horning
Finding Aid Date
September 2014
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Awards and Honors, 1970-1992.
Box 1 Folder 1
Biographical Memoir of L. B. Flexner by James M. Sprague, 1997.
Box 1 Folder 2
Biomedical Research Support Grant Application, 1985.
Box 1 Folder 3
Caricatures of L. B. Flexner by W. King, 1935, n.d.
Box 1 Folder 4
Certificate: Emeritus Professor of Anatomy, July 1970.
Box 1 Folder 5
Curricula Vitae, 1967-1989.
Box 1 Folder 6
Flexner Lecture and Prize, 1974, 1996.
Box 1 Folder 7
Flexner, Abraham: Inscribed Offprints, 1925-1930, 1950.
Box 1 Folder 8
Flexner, Abraham: Memorial Booklet, 1959.
Box 1 Folder 9
Flexner, Josefa: Curriculum Vitae, c. 1963.
Box 1 Folder 10
Flexner, Simon: Inscribed Offprints, 1934-1939.
Box 1 Folder 11
Histology Class Notes, 1975, 1990, n.d.
Box 1 Folder 12
Inscribed Offprints, 1925, 1946, 1952.
Box 1 Folder 13
Memorial for L. B. Flexner at the University of Pennsylvania, June 1996.
Box 1 Folder 14
Memos, 1951-1952.
Box 1 Folder 15
Mice Colony, 1992-1996.
Box 1 Folder 16
Obituaries, 1996.
Box 1 Folder 17
Photographs, 1938-1992.
Box 1 Folder 18
Puro Graphs, n.d.
Box 1 Folder 19
References for Class Lectures, 1961, 1966-1967.
Box 1 Folder 20
Report on University of Pennsylvania Anatomy Department, 1975-1976.
Box 1 Folder 21
Student Comments, 1987, n.d.
Box 1 Folder 22
Talks, 1949-1957.
Box 1 Folder 23
Talks re: Memory and Learning, 1963-1973.
Box 1 Folder 24
Weed, Lewis Hill: Memorial Booklet, 1952.
Box 1 Folder 25

A-B, 1939-1993.
Box 1 Folder 26
C, 1940-1991.
Box 1 Folder 27
Children's Hospital, 1966-1967.
Box 1 Folder 28
D-E, 1944-1989.
Box 1 Folder 29
Dickerson, William C., 1954.
Box 1 Folder 30
F, 1933-1992.
Box 1 Folder 31
G, 1951-1986.
Box 1 Folder 32
H, 1940-1983.
Box 1 Folder 33
K-M, 1940-1993.
Box 1 Folder 34
P-R, 1951-1986.
Box 1 Folder 35
Roberts, Richard, 1978-1979.
Box 1 Folder 36
S-V, 1940-1992.
Box 1 Folder 37
W-Z, 1934-1985.
Box 1 Folder 38

Acetoxycycloheximide-Induced Transient Amnesia: Protective Effects of Adrenergic Stimulants, 1972.
Box 1 Folder 39
ADH and Related Peptides: Effect of Pre- or Posttraining Treatment on Puromycin Amnesia, 1978.
Box 1 Folder 40
Adrenalectomy and the Suppression of Memory by Puromycin, 1970.
Box 1 Folder 41
Antitryptic Titre in Pregnancy and in Hyperthyroidism, 1929.
Box 1 Folder 42
The Biochemical Basis of Long-Term Memory, 1969.
Box 1 Folder 43
Biochemical Changes Associated with Onset of Secretion in the Fetal Choroid Plexus: An Organization of Oxidation-Reduction Processes, 1938.
Box 1 Folder 44
Biochemical Changes Associated with Onset of Secretory Activity in the Metanephros of the Fetal Pig: The Cytochrome Oxidase-Cytochrome System and Oxidation-Reduction Potentials, 1939.
Box 1 Folder 45
Biochemical and Physiological Differentiation During Morphogenesis: Parts 6-9, 11-12, 14, 16, 19-23, 1946-1958.
Box 1 Folder 46
Blockade of B1- but not of B2-adrenergic Receptors Replicates Propranolol's Suppression of the Cerebral Spread of an Engram in Mice, 1985.
Box 1 Folder 47
Blockade of Peripheral Beta-Andrenergic Receptors Fails to Suppress the Cerebral Spead of an Engram in Mice, 1985.
Box 1 Folder 48
Capillary Permeability: Rate of Transcapillary Exchange of Chloride in the Guinea Pig as Determined with Radiochloride, 1949.
Box 1 Folder 49
Capillary Permeability: Rate of Transcapillary Exchange of Iron Added to Plasma as Radioactive Ferris Beta-Globulinate, 1948.
Box 1 Folder 50
Central Nervous System Effects of Posterior Pituitary Hormones, Fragments, and Their Derivatives on Drug Tolerance/Dependence and Behavior, 1980.
Box 1 Folder 51
Cerebrospinal Elasticity in the Cat and Macaque, 1932.
Box 1 Folder 52
Changes in the Chemistry and Nature of the Cerebrospinal Fluid During Fetal Life in the Pig, 1938.
Box 1 Folder 53
The Chemistry and Nature of the Cerebrospinal Fluid, 1934.
Box 1 Folder 54
Comparison in Mice of the Amnestic Effects of Cycloheximide and 6-Hydroxydopamine in a One-Trial Passive Avoidance Task, 1976.
Box 1 Folder 55
The Comparative Physiology of Placental Transfer, 1942.
Box 1 Folder 56
Conditions of Fetal Respiration in the Goat and The Utilization of Oxygen in the Uterus in the Rabbit, 1934.
Box 1 Folder 57
The Correlation of Oxygen Consumption, Function and Structure in the Developing Metanephros of the Pig, 1937.
Box 1 Folder 58
The Cyclized C-Terminal Dipeptide of Arginine Vasopressin: Metabolic Stability and Antagonism of Puromycin-Induced Amnesia, 1982.
Box 1 Folder 59
Cycloheximide and Acetoxycycloheximide: Inhibition of Tyrosine Hydroxylase Activity and Amnestic Effects, 1973.
Box 1 Folder 60
The Determination of Radioactive Iron in Biological Material with Particular Reference to Purification and Separation of Iron with Isopropyl Ether, Ashing and Electroplating Technique, and Accuracy of the Method, 1948.
Box 1 Folder 61
The Development of the Cerebral Cortex: A Cytological, Functional, and Biochemical Approach, 1952.
Box 1 Folder 62
The Development of the Meninges in Amphibia: A Study of Normal and Experimental Animals, 1929.
Box 1 Folder 63
Developmental Physiology, 1946.
Box 1 Folder 64
Dissection of Memory in Mice with Antibiotics, 1968.
Box 1 Folder 65
Distribution, Survival and Biological Effects in Mice of a Behaviorally Active, Enzymatically Stable Peptide: Pharmacokinetics of Cyclo(Leu-Gly) and Puromycin-indiced Amnesia, 1978.
Box 1 Folder 66
Dose-Response Relationships in Attenuation of Puromycin-Induced Amnesia by Neurohypophyseal Peptides, 1977.
Box 1 Folder 67
Effect of Acetoxycycloheximide and of an Acetoxycycloheximide-Puromycin Mixture on Cerebral Protein Synthesis and Memory in Mice, 1965.
Box 1 Folder 68
The Effect of Acetoxyccycloheximide on Rate of Accumulation of Cerebral Catecholamines from Circulating Tyrosine as Related to Its Effect on Memory, 1975.
Box 1 Folder 69
The Effect of the Beta-adrenergic Receptor Antagonist, Propranolol, on the Cerebral Spread of a Memory Trace in Mice, 1983.
Box 1 Folder 70
Effect of Corticotropin and Desglycinamide-Lysine Vasopressin on Suppression of Memory by Puromycin, 1972.
Box 1 Folder 71
Effect of Two Inhibitors of Dopamine B-Hydroxylase on Maturation of Memory in Mice, 1976.
Box 1 Folder 72
The Elasticity of the Dural Sac and Its Contents, 1932.
Box 1 Folder 73
Enzymatic and Functional Patterns of the Developing Mammalian Brain, 1955.
Box 1 Folder 74
The Estimation of Extracellular and Total Body Water in the Newborn Human Infant with Radioactive Sodium and Deuterium Oxide, 1947.
Box 1 Folder 75
Events Associated with the Development of Nerve and Hepatic Cells, 1955.
Box 1 Folder 76
Factors Concerned in Positional Alterations of Intracranial Pressure, 1933.
Box 1 Folder 77
The Fine Structure of Puromycin-Induced Changes in Mouse Entorhinal Cortex, 1968.
Box 1 Folder 78
Further Observations on Restoration of Memory Lost after Treatment with Puromycin, 1969.
Box 1 Folder 79
Further Observations Upon the Monro-Kellie Hypothesis, 1932.
Box 1 Folder 80
Further Studies on the Components of Lactic Dehydrogenase of Cerebral Cortex, 1962.
Box 1 Folder 81
Glycogenesis in the Liver of the Fetal Guinea Pig, 1954.
Box 1 Folder 82
Influences of Neurohypophyseal Hormones and Related Peptides on Adaptive Phenomena in the Central Nervous System, 1982.
Box 1 Folder 83
Inhibition of Protein Synthesis in Brain and Learning and Memory Following Puromycin, 1962.
Box 1 Folder 84
Inhibition by Z-Pro-D-Leu of Development of Tolerance To and Physical Dependence on Morphine in Mice, 1978.
Box 2 Folder 1
Intracerebral Saline: Effect on Memory of Trained Mice Treated with Puromycin, 1968.
Box 2 Folder 2
Lactic Dehydrogenases of the Developing Cerebral Cortex and Liver of the Mouse and Guinea Pig, 1960.
Box 2 Folder 3
Long-Term Suppression in Mice of the Development of Complementary Memory Storage Sites: Effects of Muscarinic Antagonist, 1990.
Box 2 Folder 4
Long-Term Suppression of the Cerebral Spread of a Memory: Effects of Idazoxan and Clonidine, 1987.
Box 2 Folder 5
Long-Term Suppression of the Development of Complementary Memory Storage Sites in Mice: Functional Interdependence of Acetylcholine and Dopamine, 1994.
Box 2 Folder 6
Loss of Memory in Mice as Related to Regional Inhibition of Cerebral Protein Synthesis, 1965.
Box 2 Folder 7
Loss of Memory as Related to Inhibition of Cerebral Protein Synthesis, 1965.
Box 2 Folder 8
Loss of Recent Memory in Mice as Related to Regional Inhibition of Cerebral Protein Synthesis, 1964.
Box 2 Folder 9
Maternal Plasma as a Source of Iron for the Fetal Guinea Pig, 1950.
Box 2 Folder 10
Measurement of Placental Permeability with Radioactive Sodium, 1939.
Box 2 Folder 11
A Mechanism of Secretion in the Chorioid Plexus: The Conversion of Oxidation-Reduction Energy into Work, 1938.
Box 2 Folder 12
Memory and Cerebral Protein Synthesis in Mice as Affected by Graded Amounts of Puromycin, 1965.
Box 2 Folder 13
Memory in Mice as Affected by Intracerebral Puromycin, 1963.
Box 2 Folder 14
Memory in Mice Analyzed with Antibiotics, 1967.
Box 2 Folder 15
Memory in Mice Dissected with Antibiotics, 1967.
Box 2 Folder 16
A Model for the Development of Retina-Cortex Connections, 1966.
Box 2 Folder 17
Neurohypophyseal Hormones, Analogs and Fragments: Their Effect on Puromycin-Induced Amnesia, 1975.
Box 2 Folder 18
Note on Cerebrospinal Elasticity in a Chimpanzee, 1933.
Box 2 Folder 19
A Note on the Rate of Circulation of Cerebrospinal Fluid, 1933.
Box 2 Folder 20
On the Rate of Reaction Between Enzyme and Substrate, 1928.
Box 2 Folder 21
The Output of the Fetal Heart in the Goat, 1934.
Box 2 Folder 22
Oxidation-Reduction Potentials at Carbon and Tungsten Electrodes, 1930.
Box 2 Folder 23
Oxidation-Reduction Systems of Biological Significance: Parts One and Three, 1928-1929.
Box 2 Folder 24
The Oxygen Consumption, Cytochrome and Cytochrome Oxidase Activity and Histological Structure of the Developing Cerebral Cortex of the Fetal Pig, 1941.
Box 2 Folder 25
The Permeability of the Human Placenta to Sodium in Normal and Abnormal Pregnancies and the Supply of Sodium to the Human Fetus as Determined with Radioactive Sodium, 1948.
Box 2 Folder 26
Permeability of the Human Placenta to Water and the Supply of Water to the Human Fetus as Determined with Deuterium Oxide, 1948.
Box 2 Folder 27
Permeability of the Placenta of the Guinea Pig to Inorganic Phosphate and its Relation to Fetal Growth, 1946.
Box 2 Folder 28
Pituitary Peptides and the Suppression of Memory by Puromycin, 1971.
Box 2 Folder 29
Puromycin: Action on Neuronal Mitochondria, 1968.
Box 2 Folder 30
Puromycin: Effect on Memory of Mice When Injected with Various Cations, 1969.
Box 2 Folder 31
Puromycin's Suppression of Memory in Mice as Affected by Caffeine, 1974.
Box 2 Folder 32
Rate of Formation of Cerebrospinal Fluid in Etherized Cats, The, 1932.
Box 2 Folder 33
The Rate of Renewal in Woman of the Water and Sodium of the Amniotic Fluid as Determined by Tracer Techniques, 1948.
Box 2 Folder 34
The Rate of Transcapillary Exchange of Sodium in Normal and Shocked Dogs, 1944.
Box 2 Folder 35
The Reduction of Osmic Acid as an Indicator of Adrenal Cortical Activity in the Rat, 1939.
Box 2 Folder 36
The Relations of the Intracranial Pressures, 1933.
Box 2 Folder 37
Restoration of Expression of Memory Lost After Treatment with Puromycin, 1967.
Box 2 Folder 38
The Role of Ventricular Dilation in the Spread of Infections from the Subarach-Noid Space into the Ventricles, 1933.
Box 2 Folder 39
Some Evidence for the Involvement of Adrenergic Sites in the Memory Trace, 1970.
Box 2 Folder 40
Some Problems of the Origin, Circulation and Absorption of the Cerebrospinal Fluid, 1933.
Box 2 Folder 41
Stages of Memory in Mice Treated with Acetoxycycloheximide Before or Immediately After Learning, 1966.
Box 2 Folder 42
Studies on Capillary Permeability with Tracer Substances, 1948.
Box 2 Folder 43
Studies on Memory: The Cerebral Spread of An Engram in Mice as Affected by Inhibitors of Dopamine B-Hydroxylase, 1982.
Box 2 Folder 44
Studies on Memory: Distribution of Peptidyl-Puromycin in Subcellular Fractions of Mouse Brain, 1971.
Box 2 Folder 45
Studies on Memory: Evidence for a Widespread Memory Trace in the Neocortex After the Suppression of Recent Memory by Puromycin, 1969.
Box 2 Folder 46
Studies on Memory: Inhibitors of Protein Synthesis Also Inhibit Catecholamine Synthesis, 1975.
Box 2 Folder 47
Studies on Memory: The Long Survival of Peptidyl-Puromycin in Mouse Brain, 1968.
Box 2 Folder 48
Studies on Memory: The Reevaluation in Mice of the Effects of Inhibitors on the Rate of Synthesis of Cerebral Proteins as Related to Amnesia, 1979.
Box 2 Folder 49
Studies on Memory: Spontaneous Return of Memory in 6-Hydroxydopamine-Treated Mice and its Relation to Cycloheximide-Induced Transient Amnesia, 1977.
Box 2 Folder 50
Studies on Rates of Exchange of Substances Between the Blood and Extravascular Fluid: The Exchange of Sodium in the Guinea Pig, 1944.
Box 2 Folder 51
Studies on Rates of Exchange of Substances Between the Blood and Extravascular Fluid: The Exchange of Water in the Guinea Pig, 1942.
Box 2 Folder 52
A Study of the Development of the Cerebral Cortex of the Foetal Guinea-Pig by Means of the Ultra-Violet Miscroscope, 1956.
Box 2 Folder 53
Thermodynamic Analysis of Ultrafiltration: The Ultrafiltration of Sucrose and Colloidal Solutions, 1937.
Box 2 Folder 54
Time-Dependency of Neurohypophyseal Peptide Attenuation of Puromycin Amnesia in Mice, 1980.
Box 2 Folder 55
Transfer of Radioactive Sodium Across the Placenta of the Cat, 1940.
Box 2 Folder 56
Transfer of Radioactive Sodium Across the Placenta of the Goat, 1941.
Box 2 Folder 57
Transfer of Radioactive Sodium Across the Placenta of the Guinea Pig, 1941.
Box 2 Folder 58
Transfer of Radioactive Sodium Across the Placenta of the Rabbit, 1941.
Box 2 Folder 59
Transfer of Radioactive Sodium Across the Placenta of the Sow, 1941.
Box 2 Folder 60
Transfer of Radioactive Sodium Across the Placenta of the White Rat, 1941.
Box 2 Folder 61
The Transfer of Sodium Across the Human Placenta, 1943.
Box 2 Folder 62
The Transfer of Water and Sodium to the Amniotic Fluid of the Guinea Pig, 1942.
Box 2 Folder 63
Visual Discrimination Learning and Interhemispheric Transfer in the Cat, as Affected by 6-hydroxydopamine, n.d.
Box 2 Folder 64
The Water of the Cerebrospinal Fluid, 1933.
Box 2 Folder 65

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