Binary Matrix Shuffling Filter for Feature Selection in Neuronal Morphology Classification

Table 2

The 43 morphological characteristics extracted by L-measure software and their descriptions.

Number

Abbr.

Morphological index

Description

1

SS

Soma_surface

Somatic surface area

2

_stems

Total number of trees

3

_bifs

Total number of bifurcations

4

_branch

Number of bifurcations plus terminations

5

_tips

Number of terminal tips of a neuron

6

NW

Neuronal_width

95% of second principal component

7

NH

Neuronal_height

95% of first principal component

8

ND

Neuronal_depth

95% of third principal component

9

Ty

Type

Compartments are assigned to four different types: 1 = soma, 2 = axon, 3 = dendrites, and 4 = apical dendrites

10

Di

Diameter

Average branch diameter

11

Dp

Diameter_pow

Diameter of each compartment of the neuron raised to the power of 1.5

12

Le

Length

Total arborization length

13

Su

Surface

Surface area of each compartment

14

SA

Section area

Total arborization surface area

15

Vo

Volume

Total internal volume of the arborization

16

ED

Euc distance

Maximum euclidean (straight) distance from soma to tips

17

PD

Path distance

Maximum path (along the tree) distance from soma to tips

18

BO

Branch_order

Maximum branch order number of bifurcations from soma to tips

19

Td

Terminal degree

Total number of tips each segment will terminate into

20

TS

Terminal segment

Number of compartments that comprise the terminal branch

21

Ta1

Taper_1

The change in diameter over path length between two critical points

22

Ta2

Taper_2

The ratio of the change in diameter to the initial diameter of two critical points. The initial diameter is usually larger

23

Bpl

Branch_path length

Summation of the individual compartment lengths that form a branch

24

Co

Contraction

Average contraction (the ratio between euclidean and path length calculated on each branch)

25

Fr

Fragmentation

Total number of reconstruction points

26

DR

Daughter_ratio

Ratio between the diameter of the bigger daughter and the smaller daughter of the current bifurcation

27

PDR

Parent-daughter_ratio

Ratio between the diameter of a daughter and its father for each critical point

28

Pa

Partition_asymmetry

Average over all bifurcations of the absolute value of ( − )/( + − 2), where and are the numbers of tips in the two subtrees

29

RP

Rall_power

Average over all bifurcations of the sum of the diameters of the two daughters, elevated to 1.5, divided by the diameter of the parent, and elevated to 1.5

30

Pk

Pk

= 0, 5

31

Pc

Pk_classic

Rall power is set to 1.5

32

Pk2

Pk_2

Rall power is set to 2

33

Bal

Bif_ampl_local

Average over all bifurcations of the angle between the first two daughter compartments

34

Bar

Bif_ampl_remote

Average over all bifurcations of the angle between the following bifurcations or tips

35

Btl

Bif_tilt_local

The angles between the end of the parent branch and the initial part of the daughter branches at the bifurcation

36

Btr

Bif_tilt_remote

The angles between the previous node of the current bifurcating father and the daughter nodes

37

Btol

Bif_torque_local

Angle between the current plane of bifurcation and the previous plane of bifurcation

38

Btor

Bif_torque_remote

Angle between the current plane of bifurcation and the previous plane of bifurcation

39

Lpd

Last_parent_diam

Diameter of last bifurcation before the terminal tips

40

Dt

Diam_threshold

Diameter of first compartment after the terminal bifurcation leading to a terminal tip

41

HT

Hillman threshold

Computation of the weighted average diameter between 50% of father and 25% of daughter diameters of the terminal bifurcation

42

He

Helix

Helicity of the branches of the neuronal tree. It needs to be at least 3 compartments long to compute the helicity

43

FD

Fractal_dim

Fractal dimension metric of the branches in the dendrite trees