adding 2D array to 3D array

I have a 3D data matrix (data_3D = 285 x 1 x 32). I need to add data_3D(:,:,1) to the beginning of data_3D. For example:

data_3D=
val(:,:,1) =

0.4071
0.3264
0.2420
.
.

val(:,:,2) =

1.6763
1.7567
1.8351
.
.

val(:,:,3) =

-0.4985
-0.4467
-0.3952
.
.

When data_3D(:,:,1) is added to the beginning of data_3D, data_3D should be:

data_3D=
val(:,:,1) =

0.4071
0.3264
0.2420
.
.

val(:,:,2) =

0.4071
0.3264
0.2420
.
.

val(:,:,3) =

1.6763
1.7567
1.8351
.
.

val(:,:,4) =

-0.4985
-0.4467
-0.3952
.
.

Answer 1

[DGM]

An example:

A = randi(100,3,1,4)

A = 
A(:,:,1) =

    77
    10
    37


A(:,:,2) =

    66
    92
    64


A(:,:,3) =

    50
    26
    55


A(:,:,4) =

    34
    33
     2

B = A(:,:,[1 1:end])

B = 
B(:,:,1) =

    77
    10
    37


B(:,:,2) =

    77
    10
    37


B(:,:,3) =

    66
    92
    64


B(:,:,4) =

    50
    26
    55


B(:,:,5) =

    34
    33
     2

Alternatively, you can do the concatenation just using cat()

C = cat(3,A(:,:,1),A)

C = 
C(:,:,1) =

    77
    10
    37


C(:,:,2) =

    77
    10
    37


C(:,:,3) =

    66
    92
    64


C(:,:,4) =

    50
    26
    55


C(:,:,5) =

    34
    33
     2